Jar Testing The purpose of jar testing is to optimize treatment pH, flocculant type and dosage, the need for coprecipitants such as iron, and solids removal characteristics. Facilities should conduct jar testing on a sample of their actual wastewater to provide reliable information.

Control System Upgrades Typical treatment system controls at MP& M facilities includes pH and ORP controllers on alkaline chlorination systems for cyanide destruction, pH controllers on chemical precipitation systems, flow and level monitoring equipment on equalization tanks, and solonoid valves and metering pumps on chemical feed systems to provide accurate treatment chemical dosing. A number of MP& M facilities have computer hardware and software to monitor and change treatment system operating parameters. For a number of MP& M facilities, upgrading control equipment may reduce both pH and ORP swings caused by excess chemical dosing, resulting in consistent effluent metals concentrations.

8 56 8.0  Pollution Prevention and Wastewater Treatment Technologies Operator Training Having operators trained in both the theory and practical application of wastewater treatment is key to ensuring the systems are operating at their best. Many MP& M facilities send their operators to off site training centers while others bring consultants familiar with their facility s operations and wastewater treatment system to the facility to train operators. Some of the basic elements of an operator training course should include ( 1):

  An explanation of the need for wastewater treatment, which emphasizes the benefits to employees and the community;

  An emphasis on management s commitment to environmental stewardship;

  An explanation of wastewater treatment terminology in simple terms;

  An overview of the environmental regulations that govern the facility s wastewater discharges;

  A simple overview of wastewater treatment chemistry;

  Methods that can optimize treatment performance ( e. g., how to conduct jar testing);

  The test methods or parameters used to verify the system is operating properly ( e. g., control systems); and   The importance of equipment maintenance to ensure the system is operating at its maximum potential.

First time training for new operators may require 4 to 5 days of classroom and hands on study. Experienced MP& M wastewater treatment operators should consider attending at least 1 day of refresher training per year to update themselves on the chemistry and to learn about new equipment on the market that may help their system s performance.

8.5.2 Oil Removal Operations such as machining and grinding, disassembly of oily equipment, and cleaning can generate wastewater containing organic machining coolants, hydraulic oils, and lubricating oils. In addition, shipbuilding facilities may commingle oily bilge water with wastewater from other shore side operations, resulting in a mixed oily wastewater. Information collected during MP& M site visits, sampling episodes, and from the MP& M detailed surveys showed a variety of methods to treat oily wastewater. The primary treatment technologies are 8 57 8.0  Pollution Prevention and Wastewater Treatment Technologies emulsion breaking and gravity flotation, emulsion breaking and DAF, and ultrafiltration. Section 8.4 discusses these technologies.

8.5.3 Polishing Technologies Polishing systems remove small amounts of pollutants that may remain in the effluent after treatment using technologies such as chemical precipitation and gravity clarification. These systems also can act as a temporary measure to prevent pollutant discharge should the primary solids removal system fail due to a process upset or catastrophic event. The following are descriptions of end of pipe polishing technologies that are applicable to MP& M facilities.

<IP_ADDRESS> Multimedia Filtration Sand filtration and multimedia filtration systems typically remove small amounts of suspended solids ( metal precipitates) entrained in effluent from gravity clarifiers. Sand and multimedia polishing filters usually are designed to remove 90 percent or greater of all filterable suspended solids 20 microns or larger at a maximum influent concentration of 40 mg/ L. Wastewater is pumped from a holding tank through the filter. The principal design factor for the filter is the hydraulic loading. Typical hydraulic loadings range between 4 and 5 gpm/ ft2 ( 9). Sand and multimedia filters are cleaned by backwashing with clean water. Backwashing is timed to prevent breakthrough of the suspended solids into the effluent. Figure 8 16 shows a diagram of a multimedia filtration system.

Figure 8 16. Multimedia Filtration System 8 58 8.0  Pollution Prevention and Wastewater Treatment Technologies <IP_ADDRESS> Activated Carbon Adsorption Activated carbon adsorption removes dissolved organic compounds from wastewater. Some MP& M facilities use carbon adsorption to polish effluent from ultrafiltration systems treating oily wastewater. During adsorption, molecules of a dissolved compound adhere to the surface of an adsorbent solid. Activated carbon is an excellent adsorption medium due to its large internal surface area, generally high attraction to organic pollutants, and hydrophobic nature ( i. e., water will not occupy bonding sites and interfere with the adsorption of pollutants). Pollutants in the wastewater bond on the activated carbon grains until all the surface bonding sites are occupied. At that point, the carbon is considered to be   spent.  Spent carbon requires regeneration; regenerated carbon has a reduced adsorption capacity compared to fresh carbon. After several regenerations, the carbon is disposed of.

The carbon fits in granular carbon system vessels, forming a   filter  bed. Vessels are usually circular for pressure systems and rectangular for gravity flow systems. For wastewater treatment, activated carbon typically is packed into one or more filter beds or columns; a typical treatment system consists of multiple filter beds in series. Wastewater flows through the filter beds and comes in contact with all portions of the activated carbon. The activated carbon in the upper portion of the column is spent first ( assuming flow is downward), and progressively lower regions of the column are spent as the adsorption zone moves down the unit. When pollutant concentrations at the bottom of the column begin to increase above acceptable levels, the entire column is considered spent and must be regenerated or removed.

<IP_ADDRESS> Reverse Osmosis Reverse osmosis is a membrane separation technology used by MP& M facilities as an in process step or as an end of pipe treatment. Section <IP_ADDRESS> discusses in process reverse osmosis. In an end of pipe application, reverse osmosis typically recycles water and reduces discharge volume rather than recovers chemicals. The effluent from a conventional treatment system generally has a TDS concentration unacceptable for most rinsing operations, and cannot be recycled. Reverse osmosis with or without some pretreatment can replace TDS concentrations, and the resulting effluent stream can be used for most rinsing operations.

<IP_ADDRESS> Ion Exchange Ion exchange is both an in process metals recovery and recycle and end of pipe polishing technology. Section <IP_ADDRESS> discusses in process ion exchange. This technology generally uses cation resins to remove metals but sometimes uses both cation and anion columns. The regenerant from end of pipe ion exchange is not usually amenable to metals recovery as it typically contains multiple metals at low concentrations.

8 59 8.0  Pollution Prevention and Wastewater Treatment Technologies 8.5.4 Sludge Handling This subsection discusses the following sludge handling technologies:

  Gravity thickening;

  Pressure filtration;

  Sludge drying; and   Vacuum filtration.

<IP_ADDRESS> Gravity Thickening Gravity thickening is a physical liquid solid separation technology used to dewater wastewater treatment sludge. Sludge feeds from a primary settling tank or clarifier to a thickening tank, where gravity separates the supernatant ( liquid) from the sludge, increasing the sludge density. The supernatant returns to the primary settling tank or the head of the treatment system for further treatment. The thickened sludge that collects on the bottom of the tank is pumped to additional dewatering equipment or contract hauled for disposal. Figure 8 17 shows a diagram of a gravity thickener.

Figure 8 17. Gravity Thickening Facilities where the sludge is to be further dewatered by a mechanical device, such as a filter press, generally use gravity thickeners. Increasing the solids content in the thickener substantially reduces capital and operating costs of the subsequent dewatering device and also reduces the hauling cost. This process is potentially applicable to any MP& M facility that generates sludge.

8 60 8.0  Pollution Prevention and Wastewater Treatment Technologies <IP_ADDRESS> Pressure Filtration The filter press is the most common type of pressure filtration used at MP& M facilities for dewatering wastewater treatment sludges. A filter press consists of a series of parallel plates pressed together by a hydraulic ram ( older models may have a hand crank), with cavities between the plates. Figure 8 18 shows a diagram of a plate and frame filter press. The filter press plates are concave on each side to form cavities and are covered with a filter cloth. At the start of a cycle, a hydraulic pump clamps the plates tightly together and a feed pump forces a sludge slurry into the cavities of the plates. The liquid ( filtrate) escapes through the filter cloth and grooves molded into the plates and is forced by the pressure of the feed pump ( typically around 100 psi) to a discharge port. The filter cloth retains the solids, which remain in the cavities. This process continues until the cavities are packed with sludge solids. Some units use an air blow down manifold at the end of the filtration cycle to drain remaining liquid from the system, further drying the sludge. The pressure releases and the plates separate. The sludge solids or cake is loosened from the cavities and falls into a hopper or drum. A plate filter press can produce a sludge cake with a dryness of approximately 20 to 30 percent solids for metal hydroxides precipitated with sodium hydroxide, and 30 to 40 percent solids for metal hydroxides precipitated with calcium hydroxide. Filter presses are available in a very wide range of capacities ( 0.6 ft3 to 20 ft3 ). A typical operating cycle is from 4 to 8 hours, depending on the dewatering characteristics of the sludge. Units are usually sized based on one or two cycles per day.

Figure 8 18. Plate and Frame Filter Press 8 61 8.0  Pollution Prevention and Wastewater Treatment Technologies <IP_ADDRESS> Vacuum Filtration Some MP& M facilities conduct vacuum filtration to reduce the water content of metal hydroxide sludge. These MP& M facilities generally use cylindrical drum vacuum filters. The filters on these drums typically are either made of natural or synthetic fibers, or a wire mesh fabric. The drum dips into a vat of sludge and rotates slowly. A vacuum inside the drum draws sludge to the filter. Water is drawn through the filter to a discharge port, and the dewatered sludge is scraped from the filter. Because dewatering sludge with a vacuum filter is relatively expensive per kilogram of water removed, the liquid sludge is frequently gravity thickened prior to vacuum filtration. Figure 8 19 shows a typical rotary vacuum filter. Municipal treatment plants and a wide variety of industries frequently use vacuum filters. Larger facilities more commonly use this technology, as they may have a gravity thickener to double the solids content of clarifier sludge before vacuum filtering. Often facilities apply a precoat to inhibit filter blinding.

Figure 8 19. Rotary Vacuum Filter Maintenance of vacuum filters involves cleaning or replacing the filter media, drainage grids, drainage piping, filter parts, and other parts. Since maintenance time may be as high as 20 percent of total operating time, facilities may maintain one or more spare units. If this technology is used intermittently, the facility may drain and wash the filter equipment each time it is taken out of service.

8 62 8.0  Pollution Prevention and Wastewater Treatment Technologies <IP_ADDRESS> Sludge Drying Wastewater treatment sludges are often hauled long distances to disposal facilities. The transportation and disposal costs depend mostly on the volume and weight of sludge, which is directly related to its water content. Therefore, many MP& M facilities use sludge drying equipment following dewatering to further reduce the volume and weight of the sludge. The solids content of the sludge dewatered on a filter press usually ranges from 20 to 40 percent. Drying equipment can produce a waste material with a solids content of approximately 90 percent.

There are several design variations for sludge drying equipment. A commonly used system consists of an auger or conveyor system to move a thin layer of sludge through a drying region and discharge it into a hopper. Various heat sources including electric, electric infrared, steam, and gas are used for sludge drying. Some continuous units are designed such that the sludge cake discharged from a filter press drops into the feed hopper of the unit, making the overall dewatering process more automated. System capacities range from less than 1 ft3 / hr to more than 20 ft3 / hr of feed. Sludge drying equipment requires an air exhaust system due to the fumes generated during drying.

References 1. Freeman, H. M. Hazardous Waste Minimization . McGraw Hill Publishing Co., 1990, p. 39.

2. U. S. Environmental Protection Agency. Development Document for Effluent Limitations Guidelines and Standards for the Nonferrous Metals Forming and Metal Powders Point Source Category . EPA 440 1 86 019, September 1996.

3. Cushnie, George C. Pollution Prevention and Control Technology for Plating Operations . National Center for Manufacturing Sciences, 1994.

4. Brown, T. and LeMay, H. Chemistry  The Central Science, 2nd Edition . Prentice Hall, Inc., 1981, p. 360.

5. AFCEC TR 76 13, Final Report: Ozone Oxidation of Metal Plating Cyanide Wastewater. September 1976.

6. Garrison, R. L. and Monk, C. E.   Advanced Ozone Oxidation for Complexed Cyanides.  Proceedings of the First International Symposium on Ozone for Water and Wastewater Treatment, 1973, p. 551.

7. Electric Power Research Institute. Trace Element Removal by Iron Adsorption/ Coprecipitator: Process Design Manual . EPRI GS 7005, October 1990.

8 63 8.6 8.0  Pollution Prevention and Wastewater Treatment Technologies 8. Benefield, L. and Judkins, J. Process Chemistry for Water and Wastewater Treatment . Prentice Hall, Inc., 1982, p. 110.

9. Metcalf & Eddy, Inc. Wastewater Engineering: Treatment Disposal and Reuse . McGraw Hill Book Company, 1979, p. 187.

10. Freeman, H. M. Standard Handbook of Hazardous Waste Treatment and Disposal . McGraw Hill Publishing Co., 1989.

11. Cherry, K. F. Plating Waste Treatment . Ann Arbor Science, 1982.

12. Evans, F. L. Ozone in Water and Wastewater Treatment . Ann Arbor Science, 1975.

13. Harms, L. L. Chemicals in the Water Treatment Process . Water/ Engineering and Management, March 1987, pg 32.

14. Eckenfelder, W. W. Principles of Water Quality Management . CBI Publishing Co., 1980.

15. Texas Natural Resource Conservation Commission. Pollution Prevention for Cleaning and Degreasing Operations . www. eponline. com .

16. Ogunbameru, G. Reducing Water Used for Printed Circuit Board Manufacturing . Water and Wastewater Products, January 2003. www. wwp online. com .

17. U. S. EPA, Guidance Document for Developing Best Management Practices ( BMP),  EPA 833 B   93   004, 1993.

18. NDMA Source Control. Source Control Division, Orange County Sanitation District, California. March 27, 2002. www. ocsd. com.

8 64 9.0  Technology Options 9.0 TECHNOLOGY OPTIONS This section presents the technology options evaluated by EPA as the basis for the final MP& M effluent limitations guidelines and standards. It also describes EPA s rationale for selecting the technology options for the final rule. EPA used the options presented in this section as the basis for evaluating Best Practicable Control Technology Currently Available ( BPT), Best Conventional Pollutant Control Technology ( BCT), Best Available Technology Economically Achievable ( BAT), New Source Performance Standards ( NSPS), Pretreatment Standards for Existing Sources ( PSES), and Pretreatment Standards for New Sources ( PSNS).

EPA is promulgating performance based limitations and standards for the Oily Wastes Subcategory to control direct discharges. These limitation and standards do not require the use of any particular pollution prevention or wastewater treatment technology. Rather, a facility may use any combination of pollution prevention and wastewater treatment technology to comply with the limitations. Direct dischargers must also comply with NPDES regulations ( 40 CFR 122).

Section 9.1 summarizes the methodology EPA used to select the technologies included in the options. Sections 9.2 through 9.9 describe the technology options evaluated for the final effluent limitations guidelines and standards for each subcategory for each of the regulatory levels of control. Section 9.10 summarizes the options for each subcategory considered and selected in developing the effluent limitations and standards, and Figures 9 1 through 9 6 ( at the end of this section) present schematic diagrams of the options.

9.1 Technology Evaluation Methods Facilities performing proposed MP& M operations generate wastewater containing oils, organic pollutants, cyanide, hexavalent chromium, complexed metals, and dissolved metals. 1 The technology options considered for the final rule consist of pollution prevention and wastewater treatment technologies designed to reduce or eliminate the generation or discharge of pollutants from facilities performing proposed MP& M operations. EPA identified these technologies from responses to the MP& M detailed and screener surveys, MP& M site visits and sampling episodes, and technical literature. EPA then grouped the most common technologies according to the type of wastewater treated ( e. g., oily wastewater, metal bearing wastewater, cyanide bearing wastewater), and also by source reduction and pollution prevention technologies, recycling technologies, and end of pipe treatment technologies. Tables 8 1 through 8 3 in Section 8.0 show the in process and end of pipe treatment used by industry as reported in industry surveys.

1Note: EPA evaluated a number of unit operations for the May 1995 proposal, January 2001 proposal, and June 2002 NODA ( see Tables 4 3 and 4 4). However, EPA selected a subset of these unit operations for regulation in the final rule ( see Section 1.0). For this section, the term   proposed MP& M operations  means those operations evaluated for the two proposals, NODA, and final rule. The term   final MP& M operations  means those operations defined as   oily operations  ( see Section 1.0, 40 CFR 438.2( f), and Appendix B to Part 438) and regulated by the final rule.

9 1 9.0  Technology Options EPA considered a technology to be demonstrated in the industry if the technology effectively treated wastewater from proposed MP& M operations and if EPA observed the technology during at least one MP& M site visit or at least one survey respondent reported using the technology. EPA evaluated the performance of each technology in terms of percent removal and final effluent concentration using analytical data available from MP& M sampling episodes, discharge monitoring reports and periodic compliance reports, previous effluent guidelines data collection efforts, and quantitative and qualitative assessments from engineering site visits, comment submittals, and literature.

EPA evaluated several technology options for direct dischargers in the subcategories listed in the January 2001 proposal ( i. e., General Metals, Metal Finishing Job Shops, Printed Wiring Board, Non Chromium Anodizing, Steel Forming and Finishing, Oily Wastes, Railroad Line Maintenance, and Shipbuilding Dry Dock).

General Metals Subcategory EPA is not revising or establishing any limitations or standards for facilities that would have been subject to this subcategory. Such facilities will continue to be regulated by the General Pretreatment Standards ( Part 403), local limits, permit limits, and Parts 413 and/ or 433, as applicable.

9.2.1 Best Practicable Control Technology Currently Available ( BPT)

The following discussion describes the technology options considered for the proposed General Metals Subcategory. Facilities in this proposed subcategory generate metal bearing wastewater but may also generate some oily wastewater ( see Section 6.0).

Option 1 Option 1 includes segregation and preliminary treatment of oily wastewater, cyanide bearing wastewater, hexavalent chromium bearing wastewater, and complexed metal bearing wastewater, followed by chemical precipitation using either sodium hydroxide or lime, sedimentation using a clarifier, and sludge removal using gravity thickening and a filter press. Segregation of wastewater and subsequent preliminary treatment allows for the most efficient, effective, and economical means of removing pollutants in certain wastewater streams. These streams contain pollutants ( e. g., oil and grease, cyanide, hexavalent chromium, chelated metals, and organic solvents) that can inhibit the performance of chemical precipitation and sedimentation treatment, while increasing the overall treatment costs. For example, if a facility segregates its oil bearing wastewater from its metal bearing wastewater, then the facility can design an oil removal treatment technology based on only the oily waste flow volume and not on the combined metal bearing and oil bearing wastewater flow, decreasing the size of the overall treatment system. Treatment chemical costs are also reduced because of the reduced volume. Preliminary treatment technologies for these types of wastewater streams are described below.

9 2 9.2 9.0  Technology Options ( see Section 5.0 and Appendix C for a more detailed description of each of these wastewater streams).

  Oil Bearing Wastewater. Alkaline cleaning wastewater and water based metal working fluids ( e. g., machining and grinding coolants) typically contain significant amounts of oil and grease. These wastewater streams require preliminary treatment to remove oil and grease and organic pollutants. Option 1 includes a preliminary treatment step for these wastewaters consisting of chemical emulsion breaking followed by gravity separation of oil and water ( oil/ water separator or gravity flotation).

  Cyanide Bearing Wastewater. The industry generates several types of wastewater that may contain significant amounts of cyanide, such as electroplating and cleaning wastewater. Option 1 includes a preliminary treatment step for these wastewaters consisting of alkaline chlorination with sodium hypochlorite.

  Hexavalent Chromium Bearing Wastewater. The industry generates several types of wastewater that contain hexavalent chromium, usually from acid treatment, anodizing, conversion coating, and electroplating. Because hexavalent chromium does not form an insoluble hydroxide, this wastewater requires chemical reduction of the hexavalent chromium to trivalent chromium prior to chemical precipitation and sedimentation. Trivalent chromium forms an insoluble hydroxide and is treated by chemical precipitation and sedimentation. Option 1 includes a preliminary treatment step for these wastewaters consisting of chromium reduction using sodium metabisulfite.

  Chelated Metal Bearing Wastewater. Electroless plating and some cleaning operations generate wastewater that contains significant amounts of chelated metals. This wastewater requires chemical reduction to break the metal chelate bond or reduce the metal chelate complex to an insoluble state so that it can be removed during chemical precipitation. Option 1 includes a preliminary treatment step for these wastewaters consisting of chemical reduction using sodium borohydride, dithiocarbamate, hydrazine, or sodium hydrosulfite.

  Organic Solvent Bearing Wastewater. Option 1 also includes contract hauling of solvent degreasing wastewater, where applicable. Based on the MP& M surveys and site visits, most solvent degreasing operations that use organic solvents ( e. g., 1,1,1 trichloroethane, trichloroethene) are contract hauled for off site recycling. Some facilities performing proposed MP& M operations reported using organic solvent/ water mixtures or rinses 9 3 9.0  Technology Options following organic solvent degreasing. EPA found contract hauling of this wastewater to be the most common disposal method for these sites.

After pretreatment of the applicable segregated streams, the Option 1 technology basis is chemical precipitation and gravity clarification. Chemical precipitation adjusts the pH of the wastewater with alkaline chemicals such as lime ( calcium hydroxide) or caustic ( sodium hydroxide) or acidic chemicals ( such as sulfuric acid) to produce insoluble metal hydroxides. This step is followed by a gravity settling process in a clarifier to remove the precipitated and flocculated metal hydroxides. Sludge is then thickened in a gravity thickening unit. The sludge is then sent to a filter press used to remove excess wastewater, which is generally recycled back to the clarifier.

The technology components that many facilities performing proposed MP& M operations currently use are equivalent to those described for Option 1. Differences in the level of performance ( i. e., effluent limitations) between current discharges and Option 1 derive from improvements in operation and control of process operations and pollutant control technology. EPA s technical database developed for this rule, including industry survey, site visit, and sampling information collected during the period from 1989 through 2001, demonstrate significant progress by the industry in reducing pollutants in wastewater discharges beyond the existing regulatory standards. For example, sites are moving toward greater implementation of pollution prevention and water reduction, including progression to zero discharge when possible. In addition, improvements in treatment controls allow for more automated controls, which leads to more consistent process operation and wastewater treatment. Finally, advances in wastewater treatment chemicals also result in higher treatment efficiencies.

Option 2 Option 2 builds on Option 1 by adding the following in process pollution prevention, recycling, and water conservation methods that allow for recovery and reuse of materials:

  Two stage countercurrent cascade rinsing for all flowing rinses;

  Centrifugation and recycling of painting water curtains; and   Centrifugation, pasteurization, and recycling of water soluble machining coolants.

Option 2S Option 2S includes the technologies that compose Option 2 plus a sand filter after the clarifier to further remove residual suspended solids from chemical precipitation and clarification effluent.

9 4 9.0  Technology Options Option 3 In Option 3, an ultrafilter replaces the Option 1 chemical emulsion breaking and oil/ water separator to remove oil and grease, and a microfilter replaces the Option 1 clarifier.

Option 4 Option 4 includes the technologies in Option 3 plus the in process flow control and pollution prevention technologies described in Option 2, allowing recovery and reuse of materials along with water conservation.

Best Professional Judgment ( BPJ) to Part 433 Option EPA also considered transferring limitations from existing Metal Finishing effluent guidelines ( 40 CFR 433) to the General Metals Subcategory. The technology basis for Part 433 includes the following: ( 1) segregation of wastewater streams; ( 2) preliminary treatment steps as necessary ( including oils removal using chemical emulsion breaking and oil/ water separation, alkaline chlorination for cyanide destruction, reduction of hexavalent chromium, and chelation breaking); ( 3) chemical precipitation using sodium hydroxide; ( 4) sedimentation using a clarifier; and ( 5) sludge removal ( i. e., gravity thickening and filter press).

Option Selection Discussion As discussed in the 2001 proposal ( see 66 FR 451), EPA dropped Options 1 and 3 from further consideration because Options 2 and 4, respectively, cost less and provided greater pollutant removals. After proposal, EPA also dropped Option 4 from further consideration for the final rule because of its increased cost and lack of significant additional pollutant removals beyond Option 2. In addition, comments submitted on the proposed rule questioned the completeness of EPA s database on microfiltration ( Option 4), noting that EPA transferred limitations for several pollutants from the Option 2 technology based on lack of data.

EPA dropped Option 2S from further consideration for the final rule for the reasons outlined in the 2002 Notice of Data Availability ( NODA) ( 67 FR 38767). First, Option 2S results in greatly increased cost and minimal increased pollutant removals beyond Option 2. Second, EPA believes, after incorporating additional treatment performance data and revising the statistical methodology used for calculating numerical limitations ( see Section 10.0), the Option 2 limitations are consistently achievable without adding a sand filter. Therefore, for the final rule, EPA considered Option 2 and   BPJ to Part 433 Option  as the basis for limitations for BPT for the General Metals Subcategory. See Sections 11.0 and 12.0 for the final estimated compliance costs and pollutant removals for Option 2.

EPA proposed to establish BPT limitations for existing direct dischargers in the General Metals Subcategory based on the Option 2 technology. EPA evaluated the cost of achieving effluent reductions, pollutant reductions, and the economic achievability of compliance 9 5 9.0  Technology Options with BPT limitations based on the Option 2 technology and the level of the pollutant reductions resulting from compliance with such limitations. EPA has decided not to establish BPT limitations for existing direct dischargers in the proposed General Metals Subcategory. The 2001 proposal also contains detailed discussions on why EPA rejected BPT limitations based on other BPT technology options ( see 66 FR 452). The information in the rulemaking record for the final rule provides no basis for EPA to change this conclusion.

Those facilities potentially regulated in the General Metals Subcategory include facilities that are currently subject to effluent limitations guideline regulation under 40 CFR 433 as well as facilities not currently subject to national regulation. Approximately 263 of the 266 existing General Metals direct dischargers ( estimated from survey weights for 31 surveyed facilities) are currently covered by the Metal Finishing effluent guidelines at Part 433. The remaining three facilities ( estimated from a survey weight for one surveyed facility) are currently directly discharging metal bearing wastewaters ( e. g., salt bath descaling) but are not covered by existing Metal Finishing effluent guidelines. EPA s review of discharge monitoring data and unit operations for this surveyed non 433 General Metals facility ( with a survey weight of approximately three) indicates that this facility is already achieving Part 433 limitations because this facility has discharges that closely mirror those required by Part 433.

The facilities that are currently subject to Part 433 regulations and those facilities achieving Part 433 discharge levels, in most cases, have already installed effective pollution control technology that includes many of the components of the Option 2 technology. Approximately 30 percent of the direct discharging facilities in the General Metals Subcategory currently use chemical precipitation followed by a clarifier. Further, EPA estimates that compliance with BPT limitations based on the Option 2 technology would result in no closures of the existing direct dischargers in the General Metals Subcategory. EPA also notes that the adoption of this level of control would also reduce the pollutants discharged into the environment by facilities in this subcategory. For facilities in the General Metals Subcategory at Option 2, EPA estimates an annual compliance cost of $ 23.7 million ( 2001$). Using the method described in Section 12.0 to estimate baseline pollutant loadings, EPA estimates Option 2 pollutant removals of 417,477 pounds of conventional pollutants and 33,716 pounds of priority metal and organic pollutants from current discharges into the Nation s waters.

Evaluated under its traditional yardstick, EPA calculated that the effluent reductions are achieved at a cost of $ 18.1/ pound pollutant removed ( 2001$) for the General Metals Subcategory at Option 2. To estimate all pounds of pollutant removed by Option 2 technology for direct dischargers in the General Metals Subcategory, EPA used the revised method described in Section 12.0 to estimate baseline pollutant loadings as the sum of chemical oxygen demand ( COD) pounds removed plus the sum of all metals pounds removed. EPA used the combination of COD pounds removed plus the sum of all metals pounds removed to avoid any significant double counting of pollutants.

As previously stated, EPA received many comments on its estimation of baseline pollutant loadings and reductions for the various options presented in the January 2001 proposal.

9 6 9.0  Technology Options In response to these comments, EPA solicited comment in the June 2002 NODA on alternative methods to estimate baseline pollutant loadings. Commentors on the NODA were generally supportive of EPA s alternative methods to estimate baseline pollutant loadings. In particular, commentors noted that more accurate estimates of baseline pollutant loadings could be achieved by using DMR data. In response to these NODA comments, EPA combined the alternative methods in the NODA into the EPA Costs & Loadings Model for the final rule ( see Sections 11.0 and 12.0).

EPA also received comment on the parameter or parameters it should use for estimating total pounds removed by the selected technology option. EPA selected the sum of COD and all metals pounds removed for the final rule to compare effluent reductions and compliance costs. This approach avoided any significant double counting of pollutants and also provided a reasonable estimate of total pounds removed by Option 2 for the General Metals Subcategory. Option 2 technology segregates wastewaters into at least five different waste streams, each of which have one or two treatment steps. For example, segregated oily wastewaters have two treatment steps under Option 2 technology as they are first treated by chemical emulsion breaking oil/ water separation and then by chemical precipitation and sedimentation. These segregated wastestreams can be loosely grouped together as either oily wastewaters or metal bearing wastewaters. EPA s use of COD pounds removed for Option 2 technology generally represents the removal of pollutants from the segregated oily wastewaters. EPA s use of total metals pounds removed for Option 2 technology generally represents the removal of pollutants from the segregated metal bearing wastewaters.

EPA also considered alternative parameters for calculating total pounds removed by Option 2 for the comparison of effluent reductions and compliance costs for the General Metals Subcategory. In particular, EPA calculated a ratio of less than $ 14/ pound pollutant removed ( 2001$) for the General Metals Subcategory at Option 2 when EPA used the highest set of pollutants removed per facility with no significant double counting of pollutants ( i. e., highest per facility pollutant removals of: ( 1) COD plus total metals; ( 2) oil and grease ( as HEM) plus total metals; or ( 3) oil and grease ( as HEM) plus total suspended solids ( TSS)). EPA used the highest per facility pollutant removals as a confirmation of its primary method for calculating baseline pollutant loadings ( see Section 12.0) and Option 2 for General Metals Subcategory.

Based on the revisions and corrections to the EPA Costs & Loadings Model discussed in the June 2002 NODA and in Sections 11.0 and 12.0, EPA has decided not to adopt BPT limitations based on Option 2 technology. A number of factors supports EPA s conclusion that BPT limitations based on Option 2 technology do not represent effluent reduction levels attainable by the best practicable technology currently available. As previously noted, a substantial number of facilities that would be subject to limitations as General Metals facilities are already regulated by BPT/ BAT Part 433 limitations and other facilities are de facto Part 433 facilities if characterized by their discharges. Thus, establishing BPT limitations for a new General Metals Subcategory would effectively revise existing BPT/ BAT limitations with respect to those facilities. In this case, EPA felt that since the Agency is revising BPT/ BAT limitations for a significant portion of an industry, it should further review the effluent reductions achieved,

9 7 9.0  Technology Options and corresponding costs, for Option 2 technology. Such an examination shows that, while the Option 2 technology would remove additional pollutants at costs in the middle of the range EPA has traditionally determined are reasonable, the costs of the additional removals of toxic pollutants are substantially greater. In developing the final rule, EPA determined that, where a substantial portion of a subcategory is already subject to effluent limitations guidelines that achieve significant removal, the Agency should not promulgate the proposed BPT limitations because the limitations would achieve additional toxic removals at a cost ($ 1,000/ pound equivalent ( PE) in 1981$) substantially greater than that EPA has typically imposed for BAT technology in other industries ( generally less than $ 200/ PE in 1981$).

EPA also considered transferring limitations from existing Metal Finishing effluent guidelines ( 40 CFR 433) to the General Metals Subcategory. The technology basis for Part 433 includes the following: ( 1) segregation of wastewater streams; ( 2) preliminary treatment steps as necessary ( including oils removal using chemical emulsion breaking and oil/ water separation, alkaline chlorination for cyanide destruction, reduction of hexavalent chromium, and chelation breaking); ( 3) chemical precipitation using sodium hydroxide; ( 4) sedimentation using a clarifier; and ( 5) sludge removal ( i. e., gravity thickening and filter press).

Approximately 99 percent of the existing direct dischargers in the General Metals Subcategory are currently covered by the existing Metal Finishing effluent guidelines. The remaining 1 percent ( an estimated three facilities nationwide based on the survey weight associated with one surveyed facility) are currently permitted to discharge metal bearing wastewaters but are not covered by the existing Metal Finishing effluent guidelines. EPA's review of discharge monitoring data and unit operations for this surveyed non 433 General Metals facility ( with a survey weight of approximately three) indicates that this facility is subject to permit limitations established on a BPJ basis that are equivalent or more stringent than Part 433 limitations. Transferring limitations from existing Metal Finishing effluent guidelines would likely result in no additional pollutant load reductions. Therefore, based on the lack of additional pollutant removals that are estimated, EPA is not promulgating BPT limitations transferred from existing Metal Finishing effluent limitations guidelines for the General Metals Subcategory.

EPA is not revising or establishing BPT limitations for any facilities in this subcategory. Direct dischargers in the General Metals Subcategory will remain regulated by permit limits and Part 433, as applicable.

9.2.2 Best Conventional Pollutant Control Technology ( BCT)

In deciding whether to adopt more stringent limitations for BCT than BPT, EPA considers whether there are technologies that achieve greater removals of conventional pollutants than those adopted for BPT, and whether those technologies are cost reasonable under the standards established by the CWA. EPA generally refers to the decision criteria as the   BCT cost test.  For a more detailed description of the BCT cost test and details of EPA s analysis, see Chapter 4 of the Economic, Environmental, and Benefits Analysis of the Final Metal Products & Machinery Rule ( EEBA) ( EPA 821 B 03 002).

9 8 9.0  Technology Options As EPA is not establishing any BPT limitations for the General Metals Subcategory, EPA did not evaluate any technologies for the final rule that can achieve greater removals of conventional pollutants. Consequently, EPA is not establishing BCT limitations for the General Metals Subcategory.

9.2.3 Best Available Technology Economically Achievable ( BAT)

EPA proposed to establish BAT limitations for existing direct dischargers in the General Metals Subcategory based on the Option 2 technology. As discussed in Section 9.2.1, EPA has decided not to establish BPT limitations based on Option 2 technology. For the same reasons, EPA is not establishing BAT limitations based on the same technology. EPA evaluated the cost of effluent reductions, pollutant reductions, and the economic achievability of compliance with BAT limitations based on the Option 2 technology.

Based on the revisions and corrections to the EPA Costs & Loadings Model discussed in the NODA, preamble to the final rule, and in Sections 11.0 and 12.0, EPA determined that the costs of Option 2 are disproportionate to the toxic pollutant reductions ( measured in PE). The cost of achieving the effluent reduction ( in 1981$) for Option 2 for direct dischargers in the General Metals Subcategory is over $ 1,000/ PE removed ( see the EEBA and Section 26.0 of the rulemaking record, DCN 37900, for a discussion of the cost effectiveness analysis). The costs associated with this technology are, as previously noted, substantially greater than the level EPA has traditionally determined are associated with available toxic pollutant control technology. EPA has determined that Option 2 technology is not the best available technology economically achievable for existing direct dischargers in the General Metals Subcategory. Therefore, EPA is not revising or establishing BAT limitations for this subcategory based Option 2 technology.

EPA also considered transferring BAT limitations from existing Metal Finishing effluent guidelines ( 40 CFR 433.14) to the General Metals Subcategory ( see   BPJ to Part 433 Option  in Section 9.2.1). EPA reviewed existing General Metals facilities and found that all are currently achieving Part 433 BAT limitations. Transferring BAT limitations from existing Metal Finishing effluent guidelines would likely result in no additional pollutant load reductions and minimal incremental compliance costs ( see Section 9.2.1). Therefore, based on the lack of additional pollutant removals that are estimated, EPA is not promulgating BAT limitations transferred from existing Metal Finishing effluent limitations guidelines for the General Metals Subcategory.

EPA is not revising or establishing BAT limitations for any facilities in this subcategory. Direct dischargers in the General Metals Subcategory will remain regulated by permit limits and Part 433, as applicable.

9 9 9.0  Technology Options 9.2.4 New Source Performance Standards ( NSPS)

EPA proposed NSPS for the General Metals Subcategory based on Option 4 technology ( see Section 9.2.1). Option 4 technology is similar to Option 2 ( including Option 2 flow control and pollution prevention) but includes oils removal using ultrafiltration and solids separation by a microfilter ( instead of a clarifier). Commentors stated that EPA had under costed the Option 4 technology and that the compliance costs would be a barrier to entry for new facilities. In addition, commentors questioned the completeness of EPA s database on microfiltration, noting that EPA transferred standards for several pollutants from the Option 2 technology, based on lack of data. EPA reviewed its database for the Option 4 technology and agrees that its microfiltration database is insufficient to support a determination that the Option 4 limitations are technically achievable.

EPA also evaluated setting General Metals NSPS based on the Option 2 technology and assessed the financial burden to new General Metals direct dischargers. Specifically, EPA s   barrier to entry  analysis identified whether General Metals NSPS based on the Option 2 technology would pose sufficient financial burden as to constitute a material barrier to entry of new General Metals establishments into the MP& M Point Source Category. Additionally, EPA reviewed its database for establishing General Metals NSPS based on the Option 2 technology as commentors indicated the proposed standards were not technically achievable.

In response to these comments, EPA reviewed all the information currently available on General Metals facilities employing Option 2 technology. This review demonstrated that process wastewaters at General Metals facilities contain a wide variety of metals in significant concentrations. Commentors stated that single stage precipitation and solids separation steps may not achieve sufficient removals for wastewaters that contain significant concentrations of a wide variety of metals  especially if the metals preferentially precipitate at disparate pH ranges. Consequently, to address concerns raised by commentors, EPA also costed new sources to operate two separate chemical precipitation and solids separation steps in series. Two stage chemical precipitation and solids separation allows General Metals facilities with multiple metals to control metal discharges to concentrations lower than single stage chemical precipitation and solids separation over a wider pH range.

Applying this revised costing approach, EPA projects a barrier to entry for General Metals NSPS based on the Option 2 technology because 14 percent of General Metals direct dischargers have after tax compliance costs between 1 to 3 percent of revenue, 22 percent have after tax compliance costs between 3 to 5 percent of revenue, and 2 percent have after tax compliance costs greater than 5 percent of revenue. Consequently, based on the compliance costs of the modified Option 2 technology, EPA rejected Option 2 technology as the basis for NSPS in the General Metals Subcategory. See Section 11.0 for a description of how these new source compliance costs were developed and Chapter 9 of the EEBA for a description of the framework EPA used for the barrier to entry analysis and general discussion of the results.

9 10 9.0  Technology Options EPA also considered transferring NSPS from existing Metal Finishing effluent guidelines ( 40 CFR 433.16) to the General Metals Subcategory. EPA reviewed existing General Metals direct dischargers and found that all are currently either covered by or have permits based on the Metal Finishing limitations at 40 CFR 433. EPA has no basis to conclude that new General Metals facilities would have less stringent requirements than existing facilities, particularly since, in the absence of promulgated NSPS, it is likely that permit writers would consult the Part 433 requirements to establish BPJ limits. In addition, those new facilities which meet the applicability criteria for Part 433 will be subject to the NSPS for that category. Therefore, transferring standards from these existing Metal Finishing effluent limitations guidelines would likely result in no additional pollutant load reductions.

Therefore, based on the lack of additional pollutant removals that are estimated, EPA is not promulgating NSPS for the General Metals Subcategory. EPA is not revising or establishing NSPS for any facilities in this subcategory. Direct dischargers in the General Metals Subcategory will remain regulated by permit limits and Part 433, as applicable.

9.2.5 Pretreatment Standards for Existing Sources ( PSES)

As discussed in the June 2002 NODA ( 67 FR 38798), EPA also considered a number of alternative options whose economic impacts would be less costly than Option 2 technology. These options potentially have compliance costs more closely aligned with toxic pollutant reductions. EPA considered the following alternative options for the final rule:

  Option A: No change in current regulation.

  Option B: Option 2 with a higher low flow exclusion.

  Option C: Upgrading facilities currently covered by Part 413 to meet the PSES of Part 433 (  413 to 433 Upgrade Option  described below).

  Option D: Upgrading all facilities covered by Part 413 and those facilities covered by   local limits only  that discharge greater than a specified wastewater flow ( e. g., 1, 3, or 6.25 million gallons per year ( MGY)) of process wastewater to meet the PSES of Part 433 (  Local Limits to 433 Upgrade Option  described below). Note that facilities regulated by   local limits only  are also regulated by the General Pretreatment Standards ( 40 CFR 403).

413 to 433 Upgrade Option The 413 to 433 Upgrade Option would require those facilities currently required to meet the standards of the Electroplating effluent limitations guidelines ( 40 CFR 413) to meet the limitations and standards of the Metal Finishing effluent guidelines ( 40 CFR 433). Currently, the only facilities that are still completely covered by the Electroplating effluent guidelines are 9 11 9.0  Technology Options indirect dischargers that were in existence prior to 1982 and have not significantly upgraded their operations. Therefore, this alternative option applies to only a subset of indirect dischargers within the proposed General Metals, Metal Finishing Job Shops, Printed Wiring Board, and Non Chromium Anodizing Subcategories.

The technology components that compose the basis for the 413 to 433 Upgrade Option are equivalent to those described for Option 1. Differences in the level of performance ( i. e., effluent limitations) between the 413 to 433 Upgrade Option and Option 1 derive from improvements in operation and control of process operations and pollutant control technology since the early 1980s when the Electroplating effluent guidelines were developed.

Local Limits to 433 Upgrade Option This option would upgrade all facilities covered by Part 413 and those facilities covered by   local limits only  that discharge greater than a specified wastewater flow ( e. g., 1, 3, or 6.25 million gallons per year) of process wastewater to meet the PSES of Part 433. Accordingly, this technology option applies to only a subset of indirect dischargers within the proposed General Metals Subcategory. A separate but similar alternative option ( see Section 9.2.1) applies to direct dischargers.

The technology components that compose the basis for the Local Limits to 433 Upgrade Option are equivalent to those described for Option 1. Differences in treatment performance ( i. e., effluent limitations) between the Local Limits to 433 Upgrade Option and Option 1 derive from improvements in operation and control of pollutant control technology implemented since the early 1980s when the Electroplating effluent guidelines were developed.

Option Selection Discussion EPA proposed to establish PSES for existing indirect dischargers in the General Metals Subcategory based on the Option 2 technology ( i. e., the same technology basis that EPA considered for BPT/ BCT/ BAT for this subcategory) with a   low flow  exclusion of 1 MGY to reduce economic impacts on small businesses and administrative burden for control authorities. Based on the revisions and corrections to the EPA Costs & Loadings Model discussed in the NODA, preamble to the final rule, and in Sections 11.0 and 12.0, EPA rejected promulgating PSES for existing indirect dischargers in the General Metals Subcategory based on the Option 2 technology for the following reasons: ( 1) many General Metals indirect dischargers are currently regulated by existing effluent guidelines ( Parts 413 or 433 or both, as applicable); ( 2) EPA estimates that compliance with PSES based on the Option 2 technology will result in the closure of approximately 4 percent of the existing indirect dischargers in this subcategory; and ( 3) EPA determined that the incremental toxic pollutant reductions are very expensive per pound removed ( the cost effectiveness value ( in 1981$) for Option 2 for indirect dischargers in the General Metals Subcategory is $ 432/ PE).

9 12 9.0  Technology Options This suggests to EPA that the identified technology is not truly   available  to this industry because it would remove a relatively small number of additional toxic pounds at a cost significantly greater than that EPA has typically determined is appropriate for other industries. Therefore, EPA has determined that Option 2 technology is not the best available technology economically achievable for existing indirect dischargers in the General Metals Subcategory, and is not establishing PSES for this subcategory based on the Option 2 technology.

Based on the revisions and corrections to the EPA Costs & Loadings Model discussed in the NODA, preamble to the final rule, and in Sections 11.0 and 12.0, EPA has revised its methodology for estimating compliance costs and pollutant loadings for Option 2, higher low flow exclusions ( Option B), and the   upgrade  options ( Options C and D) previously described. Using information from this revised analysis, EPA concludes that all of these alternative options ( Options B, C, and D) are either not available or not economically achievable. EPA rejected Options B, C, and D because: ( 1) more than 10 percent of existing indirect dischargers not covered by Part 433 close at the upgrade option; or ( 2) toxic removals of the upgrade options are quite expensive ( cost effectiveness values ( in 1981$) in excess of $ 420/ PE), suggesting that these options are not truly available technologies for this industry segment.

EPA consequently determined that none of the treatment options represented best available technology economically achievable. Therefore, EPA is not revising or establishing PSES for existing indirect dischargers in the General Metals Subcategory ( Option A). Wastewater discharges to POTWs from facilities in this subcategory will remain regulated by local limits, General Pretreatment Standards ( Part 403), and Parts 413 and/ or 433, as applicable. EPA also notes that facilities regulated by Parts 413 and/ or 433 PSES must comply with Part 433 PSNS if the changes to their facilities are determined to make them new sources.

9.2.6 Pretreatment Standards for New Sources ( PSNS)

In 2001, EPA proposed pretreatment standards for new sources based on the Option 4 technology basis. Option 4 technology is similar to Option 2 ( including Option 2 flow control and pollution prevention) but includes oils removal using ultrafiltration and solids separation by a microfilter ( instead of a clarifier). As explained in Section 9.2.4, EPA concluded that its database is insufficient to support a determination that the Option 4 standards are technically achievable. As a result, for the final rule, EPA considered establishing PSNS in the General Metals Subcategory based on the Option 2 technology ( i. e., the same technology basis that was considered for BPT/ BCT/ BAT for this subcategory) along with the same   low flow  exemption of 1 MGY considered for existing sources.

For the final rule, EPA evaluated setting General Metals PSNS based on the Option 2 technology and assessed the financial burden to new General Metals indirect dischargers. Specifically, EPA's   barrier to entry' analysis identified whether General Metals PSNS based on the Option 2 technology would pose sufficient financial burden on new General Metals facilities to constitute a material barrier to entry into the MP& M Point Source Category.

9 13 9.0  Technology Options EPA projects a barrier to entry for General Metals PSNS based on the Option 2 technology because 14 percent of General Metals indirect dischargers have after tax compliance costs between 1 to 3 percent of revenue and 20 percent have after tax compliance costs between 3 to 5 percent of revenue. Consequently, EPA rejected Option 2 technology as the basis for PSNS in the General Metals Subcategory. EPA has selected   no further regulation,  and is not revising PSNS for new General Metals indirect dischargers. Wastewater discharges to POTWs from facilities in this subcategory will remain regulated by local limits, General Pretreatment Standards ( Part 403), and Part 433, as applicable. See Section 11.0 for a description of how these new source compliance costs were developed and Chapter 9 of the EEBA for a description of the framework EPA used for the barrier to entry analysis and general discussion of the results.

Metal Finishing Job Shops Subcategory EPA is not revising any limitations or standards for facilities that would have been subject to this subcategory. Such facilities will continue to be regulated by the General Pretreatment Standards ( Part 403), local limits, permit limits, and Parts 413 and/ or 433, as applicable.

9.3.1 BPT, BCT, and BAT EPA evaluated several technology options for direct dischargers for the Metal Finishing Job Shops ( MFJS) Subcategory. Facilities in this subcategory perform unit operations that primarily generate metal bearing wastewater, but may also generate some oily wastewater. EPA evaluated Options 1, 2, 2S, 3, and 4, which are described in detail in Section 9.2.1. As discussed in Section 9.2.1, EPA dropped Options 1, 2S, 3, and 4 from further consideration. Therefore, for the final rule, EPA considered only Option 2 as the basis for limitations for the MFJS Subcategory. See Sections 11.0 and 12.0 for the final estimated compliance costs and pollutant loadings for Option 2.

EPA proposed to establish BPT/ BCT/ BAT for existing direct dischargers in the MFJS Subcategory based on the Option 2 technology ( see Section 9.2.1 for a description of Option 2). EPA evaluated the cost of effluent reductions, pollutant reductions, and the economic achievability of compliance with BPT/ BCT/ BAT limitations based on the Option 2 technology. Based on the revisions and corrections to the EPA Costs & Loadings Model discussed in the NODA, preamble to the final rule, and in Sections 11.0 and 12.0, EPA determined that the compliance costs of the Option 2 technology are not economically achievable.

EPA estimates that compliance with BPT/ BCT/ BAT limitations based on the Option 2 technology will result in the closure of 50 percent of the existing direct dischargers in this subcategory ( 12 of 24 existing MFJS direct dischargers). Consequently, EPA concludes that, for existing direct dischargers in the MFJS Subcategory, Option 2 is not the best practicable control technology, best conventional pollutant control technology, or best available technology economically achievable. EPA has decided not to establish new BPT, BCT, or BAT limitations 9 14 9.3 9.0  Technology Options for existing MFJS direct dischargers based on the Option 2 technology; these discharges will remain subject to Part 433.

9.3.2 NSPS EPA proposed to establish NSPS for new direct dischargers in the MFJS Subcategory based on the Option 4 technology. Option 4 technology is similar to Option 2 ( including Option 2 flow control and pollution prevention) but includes oils removal using ultrafiltration and solids separation by a microfilter ( instead of a clarifier). As explained in Section 9.2.4, EPA concluded that its database is insufficient to support a determination that the Option 4 standards are technically achievable. Consequently, EPA rejected Option 4 technology as the basis for NSPS in the MFJS Subcategory.

For the final rule, EPA evaluated setting MFJS NSPS based on the Option 2 technology and assessed the financial burden to new MFJS direct dischargers. Specifically, EPA s   barrier to entry  analysis identified whether MFJS NSPS based on the Option 2 technology would pose sufficient financial burden so as to constitute a material barrier to entry into the MP& M point source category. Additionally, EPA reviewed its database for establishing MFJS NSPS based on the Option 2 technology as commentors indicated the proposed standards were not technically achievable.

In response to these comments, EPA reviewed all the information currently available on MFJS facilities using the Option 2 technology basis. This review demonstrated that process wastewaters at MFJS facilities contain a wide variety of metals in significant concentrations. Commentors stated that single stage precipitation and solids separation may not achieve sufficient removals for wastewaters that contain significant concentrations of a wide variety of metals, especially if the metals preferentially precipitate at disparate pH ranges. Consequently, to address concerns raised by commentors, EPA also costed new sources to operate two separate chemical precipitation and solids separation steps in series. Two stage chemical precipitation and solids separation allows MFJS facilities with multiple metals to control metal discharges to concentrations lower than single stage chemical precipitation and solids separation over a wider pH range.

Applying this revised costing approach, EPA projects a barrier to entry for MFJS NSPS based on the Option 2 technology because all MFJS direct dischargers have new source compliance costs that are greater than 5 percent of revenue. Consequently, EPA rejected Option 2 technology as the basis for NSPS in the MFJS Subcategory, and is not revising NSPS for new MFJS direct dischargers. Wastewater discharges from these facilities in this subcategory will remain regulated by local limits and Part 433 NSPS as applicable. See Section 11.0 for a description of how these new source compliance costs were developed and Chapter 9 of the EEBA for a description of the framework EPA used for the barrier to entry analysis and general discussion of the results.

9 15 9.0  Technology Options 9.3.3 PSES EPA evaluated several technology options for indirect dischargers for the MFJS Subcategory, whose unit operations primarily generate metal bearing wastewater, but may also generate some oily wastewater. These include the same option as evaluated for BAT ( i. e., Option 2), as well as several alternative options discussed below. EPA did not further evaluate Options 1, 2S, 3, and 4 for the final rule for the same reasons as explained for BPT above. See Sections 11.0 and 12.0 for the final estimated compliance costs and pollutant loadings for Option 2 and the alternative options considered for the final rule.

EPA proposed to establish PSES for existing indirect dischargers in the MFJS Subcategory based on the Option 2 technology. Based on the revisions and corrections to the EPA Costs & Loadings Model discussed in the NODA, preamble to the final rule, and Sections 11.0 and 12.0, EPA determined that the costs of Option 2 are not economically achievable for existing indirect dischargers in the MFJS Subcategory. EPA estimates that compliance with PSES based on the Option 2 technology will result in the closure of 46 percent of the existing indirect dischargers in this subcategory ( 589 of 1,270 existing MFJS indirect dischargers), which EPA considers to be too high. EPA has determined that Option 2 technology is not the best available technology economically achievable for existing indirect dischargers in the MFJS Subcategory. Therefore, EPA is not establishing PSES for this subcategory based on the Option 2 technology.

As discussed in the January 2001 proposal ( 66 FR 551) and June 2002 NODA ( 67 FR 38801), EPA also considered a number of alternative options whose economic impacts would be less costly than Option 2 technology. These options potentially have compliance costs more closely aligned with toxic pollutant reductions. EPA considered the following alternative options for the final rule:

  Option A: No change in current regulation;

  Option B: Option 2 with a higher low flow exclusion;

  Option C: Upgrading facilities currently covered by Part 413 to meet the PSES of Part 433 (  413 to 433 Upgrade Option  described in Section 9.2.5); and   Option D: Pollution prevention option ( see 66 FR 551).

All facilities in the MFJS Subcategory are currently subject to Part 413, Part 433 or both.

As discussed in the NODA, preamble to the final rule, and Sections 11.0 and 12.0, based on comments, EPA has revised its methodology for estimating compliance costs and pollutant loadings for Option 2, low flow exclusions ( Option B), and the   upgrade  option ( Option C) previously described. Using information from this revised analysis, EPA concludes 9 16 9.0  Technology Options that neither of these alternative options ( Options B or C) are economically achievable. EPA rejected Options B and C because more than 10 percent of existing indirect dischargers not covered by Part 433 close at the upgrade option.

EPA also solicited comment in the January 2001 proposal on a pollution prevention alternative for indirect dischargers in this subcategory ( Option D). Commentors supported Option D and stated that the pollution prevention practices identified by EPA in the January 2001 proposal represent environmentally sound practices for the metal finishing industry. The commentors also stated that Option D should, however, be implemented on a voluntary basis similar to the National Metal Finishing Strategic Goals Program ( see 66 FR 511). Control authorities also commented that Option D may increase their administrative burden because of additional review of facility operations and compliance with the approved pollution prevention plan, and enforcement of Option D may be more difficult than other options considered. EPA is not promulgating Option D for facilities in the MFJS Subcategory for the final rule due to the increased administrative burden on pretreatment control authorities and potential problems enforcing Option D. Section 8.0 describes many of the pollution prevention practices that were considered for Option D. These pollution prevention practices may be useful in helping facilities lower operating costs, improve environmental performance, and foster other important benefits.

EPA is not establishing PSES for existing indirect dischargers in the MFJS Subcategory. Wastewater discharges to POTWs from facilities in this subcategory will remain regulated by General Pretreatment Standards ( Part 403), and Parts 413 and/ or 433, as applicable. EPA also notes that facilities regulated by Parts 413 and/ or 433 PSES must comply with Part 433 PSNS if the changes to their facilities are determined to make them new sources.

9.3.4 PSNS EPA proposed to establish PSNS for indirect dischargers in the MFJS Subcategory based on the Option 4 technology. Option 4 technology is similar to Option 2 ( including Option 2 flow control and pollution prevention) but includes oils removal using ultrafiltration and solids separation by a microfilter ( instead of a clarifier). As explained in Section 9.2.4, EPA concluded its database is insufficient to support a determination that the Option 4 standards are technically achievable. Consequently, EPA rejected Option 4 technology as the basis for PSNS in the MFJS Subcategory.

For the final rule, EPA evaluated setting MFJS PSNS based on the Option 2 technology and assessed the financial burden to new MFJS indirect dischargers. Specifically, EPA's   barrier to entry' analysis identified whether MFJS PSNS based on the Option 2 technology would pose sufficient financial burden on new MFJS facilities to constitute a material barrier to entry into the MP& M Point Source Category.

EPA projects a barrier to entry for MFJS PSNS based on the Option 2 technology because 8 percent of MFJS indirect dischargers have after tax compliance costs between 1 to 3 9 17 9.0  Technology Options percent of revenue, 5 percent have after tax compliance costs between 3 to 5 percent of revenue, and 6 percent have after tax compliance costs greater than 5 percent of revenue. Consequently, EPA rejected Option 2 technology as the basis for PSNS in the MFJS Subcategory, and is not revising PSNS for new MFJS indirect dischargers. Wastewater discharges to POTWs from facilities in this subcategory will remain regulated by local limits, General Pretreatment Standards ( Part 403), and Part 433, as applicable. See Section 11.0 for a description of how these new source compliance costs were developed and Chapter 9 of the EEBA for a description of the framework EPA used for the barrier to entry analysis and general discussion of the results.

Non Chromium Anodizing Subcategory EPA is not revising limitations or standards for any facilities that would have been subject to this subcategory. Such facilities will continue to be regulated by the General Pretreatment Standards ( Part 403), local limits, permit limits, and Parts 413 and/ or 433, as applicable.

9.4.1 BPT, BCT, and BAT As previously discussed, after publication of the June 2002 NODA, EPA conducted another review of all Non Chromium Anodizing ( NCA) facilities in the MP& M survey database to determine the destination of discharged wastewater ( i. e., either directly to surface waters or indirectly to POTWs or both) and the applicability of the final rule to discharged wastewaters. As a result of this review, EPA did not identify any NCA direct discharging facilities or NCA facilities that do not discharge wastewater ( i. e., zero discharge or contract haulers) or do not use process water ( dry facilities) in its rulemaking record. All of the NCA facilities in EPA s database are indirect dischargers. Therefore, EPA cannot evaluate treatment systems at direct dischargers. As a result, EPA transferred cost and pollutant loading data from the best performing indirect facilities in order to evaluate direct discharging limitations in this subcategory.

EPA evaluated several technology options for direct dischargers for the NCA Subcategory, whose unit operations primarily generate metal bearing wastewater, but may also generate some oily wastewater. These include Options 1, 2, 2S, 3, and 4, which are described in detail in Section 9.2.1. As discussed in Section 9.2.1, EPA dropped Options 1, 2S, 3, and 4 from further consideration. Therefore, for the final rule, EPA considered only Option 2 as the basis for limitations for the NCA Subcategory. See Sections 11.0 and 12.0 for the final estimated compliance costs and pollutant loadings for Option 2.

In 2001, EPA proposed to establish BPT/ BCT/ BAT limitations for direct dischargers in the NCA Subcategory based on the Option 2 technology. EPA evaluated the cost of effluent reductions, quantity of pollutant reductions, and the economic achievability of compliance with BPT/ BCT/ BAT limitations based on the Option 2 technology. Based on the revisions and corrections to the EPA Costs & Loadings Model discussed in the NODA, preamble to the final rule, and Sections 11.0 and 12.0, the costs of the Option 2 technology were 9 18 9.4 9.0  Technology Options disproportionate to the projected toxic pollutants reductions ( cost effectiveness values ( in 1981$) in excess of $ 1,925/ PE).

EPA decided not to establish BPT/ BAT limitations based on the Option 2 technology for the NCA Subcategory for following reasons: ( 1) EPA identified no NCA direct dischargers, and ( 2) the costs of Option 2 are disproportionate to the estimated toxic pollutant reductions ( i. e., $ 1,925/ PE). EPA concludes that for existing direct dischargers in the NCA Subcategory, Option 2 is not the best practicable control technology, best conventional pollutant control technology, or best available technology economically achievable. EPA has decided not to establish new BPT, BCT, or BAT limitations for existing NCA direct dischargers based on the Option 2 technology. Although, EPA identified no NCA direct dischargers through its survey efforts, if such facilities do exist, they would be subject to Part 433.

9.4.2 NSPS EPA proposed to establish NSPS for direct dischargers in the NCA Subcategory based on the Option 2 technology. For the final rule, EPA evaluated setting NCA NSPS based on the Option 2 technology and assessed the financial burden to new NCA direct dischargers. Specifically, EPA's   barrier to entry' analysis identified whether NCA NSPS based on the Option 2 technology would pose sufficient financial burden on new NCA facilities to constitute a material barrier to entry into the MP& M Point Source Category.

EPA projects a barrier to entry for NCA NSPS based on the Option 2 technology because approximately 26 percent of NCA direct dischargers have new source compliance costs that are between 3 percent and 5 percent of revenue. Consequently, EPA rejected Option 2 technology as the basis for NSPS in the NCA Subcategory. EPA has selected   no further regulation  for new NCA direct dischargers and is not revising NSPS for new NCA direct dischargers, which will remain subject to Part 433. See Section 11.0 for a description of how these new source compliance costs were developed and Chapter 9 of the EEBA for a description of the framework EPA used for the barrier to entry analysis and general discussion of the results.

9.4.3 PSES and PSNS EPA proposed   no further regulation  for existing and new indirect dischargers in the NCA Subcategory. EPA based this decision on the economic impacts to indirect dischargers associated with Option 2 and the small quantity of toxic pollutants discharged by facilities in this subcategory, even after a economically achievable flow cutoff is applied ( see 66 FR 467). For the reasons set out in the 2001 proposal, EPA has decided not to establish new regulations and is not establishing PSES or PSNS in the NCA Subcategory. These facilities remain subject to Parts 413 or 433, or both, as applicable. EPA also notes that facilities regulated by Parts 413 and/ or 433 PSES must comply with Part 433 PSNS if the changes to their facilities are determined to make them new sources.

9 19 9.0  Technology Options 9.5 Printed Wiring Board Subcategory EPA is not revising any limitations or standards for facilities that would have been subject to this subcategory. Such facilities will continue to be regulated by the General Pretreatment Standards ( Part 403), local limits, permit limits, and Parts 413 and/ or 433, as applicable.

9.5.1 BPT, BCT, and BAT EPA evaluated several technology options for direct dischargers for the Printed Wiring Board ( PWB) Subcategory, whose unit operations primarily generate metal bearing wastewater, but may also generate some oily wastewater. These include Options 1, 2, 2S, 3, and 4, which are described in detail in Section 9.2.1. As discussed in Section 9.2.1, EPA dropped Options 1, 2S, 3, and 4 from further consideration. Therefore, for the final rule, EPA considered only Option 2 as the basis for limitations for the PWB Subcategory. See Sections 11.0 and 12.0 for the final estimated compliance costs and pollutant loadings for Option 2.

EPA proposed to establish BPT/ BCT/ BAT for direct dischargers in the PWB Subcategory based on the Option 2 technology ( see Section 9.2.1 for a description of Option 2). EPA evaluated the cost of effluent reductions, pollutant reductions, and the economic achievability of compliance with BPT/ BCT/ BAT limitations based on the Option 2 technology.

Based on MP& M survey information, EPA estimates that compliance with BPT/ BCT/ BAT limitations based on the Option 2 technology results in no closures of the existing eight direct dischargers in the PWB Subcategory. However, EPA decided not to establish BPT/ BAT limitations based on the Option 2 technology for the PWB Subcategory for the following reasons: ( 1) EPA identified only eight existing PWB direct dischargers and all of these PWB direct dischargers are currently regulated by existing effluent guidelines ( Part 433), and ( 2) the costs of Option 2 are disproportionate to the estimated toxic pollutant reductions. EPA estimates compliance costs of $ 0.3 million ( 2001$ dollars) with only 186 toxic pound equivalents ( PE) being removed. This equates to a cost effectiveness value ( in 1981$) of approximately $ 900/ PE. EPA concludes that, for existing direct dischargers in the PWB Subcategory, Option 2 is not the best practicable control technology, best conventional pollutant control technology, or best available technology economically achievable. EPA has decided not to establish new BPT, BCT, or BAT limitations for existing PWB direct dischargers based on the Option 2 technology; these discharges will remain subject to Part 433.

9.5.2 NSPS EPA proposed to establish NSPS for new direct dischargers in the PWB Subcategory based on the Option 4 technology. Option 4 technology is similar to Option 2 ( including Option 2 flow control and pollution prevention) but includes oils removal using ultrafiltration and solids separation by a microfilter ( instead of a clarifier). As explained in Section 9.2.4, EPA concluded that its database is insufficient to support a determination that the 9 20 9.0  Technology Options Option 4 standards are technically achievable. Consequently, EPA rejected Option 4 technology as the basis for NSPS in the PWB Subcategory.

For the final rule, EPA evaluated setting PWB NSPS based on the Option 2 technology. EPA reviewed its database for establishing PWB NSPS based on the Option 2 technology as commentors indicated the proposed standards were not technically achievable. In response to these comments, EPA reviewed all the information currently available on PWB facilities using the Option 2 technology basis. EPA now concludes that the PWB s Option 2 database can only be used to establish limitations for copper, nickel, and tin. In order to assess the difference between current NSPS requirements ( from Part 433) for PWB facilities and those under consideration in the final rule, EPA estimated the incremental quantities of copper, nickel, and tin that would be reduced if a new PWB facility were required to meet NSPS based on the Option 2 technology rather than NSPS based on Part 433. EPA analysis shows minimal amounts of pollutant reductions based on more stringent requirements on copper, nickel, and tin.

Consequently, EPA rejected Option 2 technology as the basis for NSPS in the PWB Subcategory based on the small incremental quantity of toxic pollutants that would be reduced in relation to existing requirements. EPA is not establishing NSPS or revising existing NSPS for new PWB direct dischargers. Wastewater discharges from these facilities in this subcategory will remain regulated by permit limits and Part 433 as applicable. See Section 11.0 for a description of how these new source compliance costs were developed and Chapter 9 of the EEBA for a description of the framework EPA used for the barrier to entry analysis and general discussion of the results.

9.5.3 PSES EPA evaluated several technology options for indirect dischargers for the PWB Subcategory, whose unit operations primarily generate metal bearing wastewater, but may also generate some oily wastewater. These include the same option as evaluated for BAT ( i. e., Option 2 as described in Section 9.2.1), as well as several alternative options described below. EPA did not further evaluate Options 1, 2S, 3, and 4 for the final rule for the same reasons as explained for BPT above. See Sections 11.0 and 12.0 for the final estimated compliance costs and pollutant loadings for Option 2 and the alternative options considered for the final rule.

EPA proposed to establish PSES for existing indirect dischargers in the PWB Subcategory based on the Option 2 technology. Based on the revisions and corrections to the EPA Costs & Loadings Model discussed in the NODA, preamble to the final rule, and Sections 11.0 and 12.0, EPA rejected promulgating PSES for existing indirect dischargers in the PWB Subcategory based on the Option 2 technology for the following reasons: ( 1) all PWB indirect dischargers are currently regulated by existing effluent guidelines ( Parts 413 or 433 or both, as applicable); ( 2) EPA estimates that compliance with PSES based on the Option 2 technology will result in the closure of 6.5 percent of the existing indirect dischargers in this subcategory ( 55 of 840 existing PWB indirect dischargers); and ( 3) EPA determined that the toxic pollutant reductions are very expensive per pound removed ( the cost effectiveness value ( in 1981$) is 9 21 9.0  Technology Options $ 455/ PE). EPA has determined that Option 2 technology is not the best available technology economically achievable for existing indirect dischargers in the PWB Subcategory, and therefore is not establishing PWB PSES based on the Option 2 technology.

As discussed in the June 2002 NODA ( see 67 FR 38802), EPA also considered a number of alternative options whose economic impacts would be less costly than Option 2 technology. These options potentially have compliance costs more closely aligned with toxic pollutant reductions. EPA considered the following alternative options for the final rule:

  Option A: No change in current regulation;

  Option B: Option 2 with a higher low flow exclusion; and   Option C: Upgrading facilities currently covered by Part 413 to the PSES of Part 433 (  413 to 433 Upgrade Option ).

EPA notes that all facilities in the PWB Subcategory are currently subject to Part 413, Part 433, or both.

As discussed in the NODA, preamble to the final rule, and Sections 11.0 and 12.0, based on comments, EPA has revised its methodology for estimating compliance costs and pollutant loadings for Option 2, higher low flow exclusions ( Option B), and the   upgrade  option ( Options C) previously described. Using information from this revised analysis, EPA rejected Options B and C because: ( 1) more than 10 percent of existing indirect dischargers not covered by Part 433 close at the upgrade option; or ( 2) the incremental compliance costs of the upgrade options were too great in terms of toxic removals ( cost effectiveness values ( in 1981$) in excess of $ 833/ PE). Therefore, EPA is not revising PSES for existing indirect dischargers in the PWB Subcategory. Wastewater discharges to POTWs from facilities in this subcategory will remain regulated by General Pretreatment Standards ( Part 403) and Parts 413 and/ or 433, as applicable. EPA also notes that facilities regulated by Parts 413 and/ or 433 PSES must comply with Part 433 PSNS if the changes to their facilities are determined to make them new sources.

9.5.4 PSNS EPA proposed to establish PSNS for indirect dischargers in the PWB Subcategory based on the Option 4 technology. Option 4 technology is similar to Option 2 ( including Option 2 flow control and pollution prevention) but includes oils removal using ultrafiltration and solids separation by a microfilter ( instead of a clarifier). As explained in Section 9.2.4, EPA concluded that its database is insufficient to support a determination that the Option 4 standards are technically achievable. Consequently, EPA rejected Option 4 technology as the basis for PSNS in the PWB Subcategory.

For the final rule, EPA evaluated setting PWB PSNS based on the Option 2 technology and assessed the financial burden to new PWB indirect dischargers. Specifically,

9 22 9.0  Technology Options EPA's   barrier to entry' analysis identified whether PWB PSNS based on the Option 2 technology would pose sufficient financial burden on new PWB facilities to constitute a material barrier to entry into the MP& M Point Source Category.

EPA projects a barrier to entry for PWB PSNS based on the Option 2 technology because 3 percent of PWB indirect dischargers have after tax compliance costs between 1 to 3 percent of revenue and 4 percent have after tax compliance costs greater than 5 percent of revenue. Consequently, EPA rejected Option 2 technology as the basis for PSNS in the PWB Subcategory. EPA has selected   no further regulation  for new PWB indirect dischargers and is not revising PSNS for new PWB indirect dischargers. Wastewater discharges to POTWs from facilities in this subcategory will remain regulated by local limits, General Pretreatment Standards ( Part 403), and Part 433, as applicable. See Section 11.0 for a description of how these new source compliance costs were developed and Chapter 9 of the EEBA for a description of the framework EPA used for the barrier to entry analysis and general discussion of the results.

Steel Forming and Finishing Subcategory EPA is not revising limitations or standards for any facilities that would have been subject to this subcategory. Such facilities will continue to be regulated by the General Pretreatment Standards ( Part 403), local limits, permit limits, and Iron and Steel effluent limitations guidelines ( Part 420), as applicable.

9.6.1 BPT, BCT, and BAT EPA evaluated several technology options for direct dischargers for the Steel Forming and Finishing ( SFF) Subcategory, whose unit operations primarily generate metal bearing wastewater, but may also generate some oily wastewater. These include Options 1, 2, 2S, 3, and 4, which are described in detail in Section 9.2.1. As discussed Section 9.2.1, EPA dropped Options 1, 2S, 3, and 4 from further consideration. Therefore, for the final rule, EPA considered only Option 2 as the basis for limitations for the SFF Subcategory. See Sections 11.0 and 12.0 for the final estimated compliance costs and pollutant loadings for Option 2.

EPA proposed to establish BPT/ BCT/ BAT for existing direct dischargers in the SFF Subcategory based on the Option 2 technology ( see Section 9.2.1 for a description of Option 2). For the final rule, EPA evaluated the cost of effluent reductions, pollutant reductions, and the economic achievability of compliance with BPT/ BCT/ BAT limitations based on the Option 2 technology. Based on the revisions and corrections to the EPA Costs & Loadings Model discussed in the NODA, preamble to the final rule, and Sections 11.0 and 12.0, EPA determined that the compliance costs of Option 2 are not economically achievable. EPA estimates that compliance with BPT/ BCT/ BAT limitations based on the Option 2 technology will result in the closure of 17 percent of the existing direct dischargers in this subcategory ( 7 of 41 existing SFF direct dischargers). EPA concludes that, for existing direct dischargers in the SFF Subcategory, Option 2 is not the best practicable control technology, best conventional pollutant control technology, or best available technology economically achievable, and therefore, EPA is not 9 23 9.6 9.0  Technology Options establishing new BPT, BCT, or BAT limitations for existing SFF direct dischargers based on the Option 2 technology. These facilities will remain subject to Part 420.

9.6.2 NSPS EPA proposed to establish NSPS for new direct dischargers in the SFF Subcategory based on the Option 4 technology. Option 4 technology is similar to Option 2 ( including Option 2 flow control and pollution prevention) but includes oils removal using ultrafiltration and solids separation by a microfilter ( instead of a clarifier). As explained in Section 9.2.4, EPA concluded that its database is insufficient to support a determination that the Option 4 standards are technically achievable. Consequently, EPA rejected Option 4 technology as the basis for NSPS in the SFF Subcategory. EPA has selected   no further regulation  for new SFF direct dischargers and is not revising NSPS for new SFF direct dischargers, which will remain subject to Part 420.

9.6.3 PSES EPA evaluated several technology options for indirect dischargers for the Steel Forming and Finishing Subcategory, whose unit operations primarily generate metal bearing wastewater, but may also generate some oily wastewater. For the final rule, EPA considered the same option as evaluated for BAT ( i. e., Option 2). EPA did not further evaluate Options 1, 2S, 3, and 4 for the final rule for the same reasons as explained for BPT above. See the Development Document for the Proposed Effluent Limitations Guidelines and Standards for the Metal Products & Machinery Point Source Category ( EPA 821 B 00 005) for the final estimated compliance costs and pollutant loadings for Option 2.

EPA proposed to establish PSES for existing indirect dischargers in the SFF Subcategory based on the Option 2 technology. Based on the revisions and corrections to the EPA Costs & Loadings Model discussed in the NODA, preamble to the final rule, and Sections 11.0 and 12.0, EPA estimates that compliance with PSES based on the Option 2 technology will result in the closure of 9 percent of the existing indirect dischargers in this subcategory ( 10 of 112 existing SFF indirect dischargers).

EPA has determined that Option 2 technology is not the best available technology economically achievable for existing indirect dischargers in the SFF Subcategory, and therefore EPA is not revising PSES for this subcategory based on the Option 2 technology. Wastewater discharges to POTWs from these facilities will remain regulated by General Pretreatment Standards ( Part 403) and Part 420.

9.6.4 PSNS EPA proposed to establish PSNS for indirect dischargers in the SFF Subcategory based on the Option 4 technology. Option 4 technology is similar to Option 2 ( including Option 2 flow control and pollution prevention) but includes oils removal using ultrafiltration and solids 9 24 9.0  Technology Options separation by a microfilter ( instead of a clarifier). As explained in Section 9.2.4, EPA concluded its database is insufficient to support a determination that the Option 4 standards are technically achievable. Consequently, EPA rejected Option 4 technology as the basis for PSNS in the SFF Subcategory. EPA has selected   no further regulation  for new SFF indirect dischargers and is not revising PSNS for new SFF indirect dischargers; these facilities will remain subject to Part 420.

Oily Wastes Subcategory EPA is promulgating limitations and standards for existing and new direct dischargers in the Oily Wastes Subcategory based on the proposed Option 6 technology ( see Section 9.7.1). EPA is not promulgating pretreatment standards for existing or new indirect dischargers in this subcategory.

9.7.1 BPT EPA evaluated several technology options for the direct dischargers in the Oily Wastes Subcategory. Each of these options is discussed below. As discussed in Section 6.0, EPA defines the Oily Wastes Subcategory as those facilities that only discharge wastewater from one or more oily operations ( see Table 6 2 and 40 CFR 438.2( f)).

Option 5 Option 5 consists of end of pipe chemical emulsion breaking followed by gravity separation using an oil/ water separator. EPA performed sampling episodes at several facilities in the Oily Wastes Subcategory that used chemical emulsion breaking followed by gravity flotation and oil skimming. These systems typically achieved a 96 percent removal of oil and grease. Breaking the oil/ water emulsion requires adding treatment chemicals such as acid, alum, and/ or polymers to change the emulsified oils or cutting fluids from hydrophilic colloids to aggregate hydrophobic particles. The aggregated oil particles, with a density less than water, can be removed by gravity flotation in a coalescing plate oil/ water separator. Option 5 also includes contract hauling of organic solvent bearing wastewaters instead of discharge.

Option 6 Option 6 consists of the technologies in Option 5 plus the following in process flow control and pollution prevention technologies, which allow for recovery and reuse of materials along with water conservation:

  Two stage countercurrent cascade rinsing for all flowing rinses;

  Centrifugation and recycling of painting water curtains; and 9 25 9.7 9.0  Technology Options   Centrifugation, pasteurization, and recycling of water soluble machining coolants.

Option 7 Option 7 consists of end of pipe ultrafiltration, as well as contract hauling of organic solvent bearing wastewater instead of discharge. Sampling episode data determined that, on average, ultrafilters will remove greater than 99 percent of all oil and grease in the influent stream.

Option 8 Option 8 consists of the Option 7 technology ( ultrafiltration) plus the pollution prevention and water conservation alternatives described in Option 6.

Option Selection As discussed in the 2001 proposal ( 66 FR 451), EPA dropped Options 5 and 7 from further consideration because Options 6 and 8, respectively, cost less and provided greater pollutant removals. Subsequent to proposal, EPA also dropped Option 8 from further consideration for the final rule because of its increased cost and lack of significant additional pollutant removals beyond Option 6. Therefore, for the final rule, EPA considered only Option 6 as the basis for limitations for the Oily Wastes Subcategory. See Sections 11.0 and 12.0 for the final estimated compliance costs and pollutant loadings for Option 6.

EPA is establishing BPT pH limitations and daily maximum limitations for two pollutants, oil and grease as hexane extractable material ( oil and grease ( as HEM)) and total suspended solids ( TSS), for direct dischargers in the Oily Wastes Subcategory based on the proposed technology option ( Option 6). Option 6 technology includes the following treatment measures: ( 1) in process flow control and pollution prevention; and ( 2) oil/ water separation by chemical emulsion breaking and skimming ( see above for additional details on the Option 6 technology).

The Agency concluded that the Option 6 treatment technology represents the best practicable control technology currently available and should be the basis for the BPT Oily Wastes limitations for the following reasons. First, this technology is available and readily applicable to all facilities in the Oily Wastes Subcategory. Approximately 42 percent of the direct dischargers in the Oily Wastes Subcategory currently use the Option 6 technology. Second, the cost of compliance with these limitations in relation to the effluent reduction benefits is not wholly disproportionate. None of these wastewater discharges are currently subject to national effluent limitations guidelines and the final rule will control wastewater discharges from a significant number ( 2,382) of facilities.

9 26 9.0  Technology Options EPA estimates that compliance with BPT limitations based on Option 6 technology will result in no closures of the existing direct dischargers in the Oily Wastes Subcategory. Moreover, the adoption of this level of control will significantly reduce the amount of pollutants discharged into the environment by facilities in this subcategory. For facilities in the Oily Wastes Subcategory at Option 6, EPA estimates an annual compliance cost of $ 13.8 million ( pre tax, 2001$) and 480,325 pounds of conventional pollutants removed from current discharges into the Nation s waters at a cost of $ 28.73/ pound pollutant removed ( 2001$). EPA has, therefore, determined that the total cost of effluent reductions as a result of using the Option 6 technology are reasonable in relation to the effluent reduction benefits. ( In estimating the pounds of pollutant removed by implementing Option 6 technology for direct dischargers in the Oily Wastes Subcategory, EPA used the sum of oil and grease ( as HEM) and TSS pounds removed to avoid any significant double counting of pollutants).

The 2001 proposal also contains detailed discussions explaining why EPA rejected BPT limitations based on other BPT technology options ( see 66 FR 457). The information in the record for the final rule provides no basis for EPA to change this conclusion.

In the 2001 proposal, EPA proposed to regulate sulfide in addition to pH, oil and grease ( as HEM), and TSS. In the final rule, EPA has not established a sulfide limitation because it may serve as a treatment chemical ( see Section 7.0). EPA also proposed three alternatives to control discharges of toxic organics in MP& M process wastewaters: ( 1) meet a numerical limit for the total sum of a list of specified organic pollutants ( similar to the Total Toxic Organic ( TTO) parameter used in the Metal Finishing effluent limitations guidelines); ( 2) meet a numerical limit for total organic carbon ( TOC) as an indicator parameter; or ( 3) develop and certify the implementation of an organic chemicals management plan. EPA evaluated the analytical wastewater and treatment technology data from Oily Wastes facilities and concluded it should not establish a separate indicator parameter or control mechanism for toxic organics. Optimizing the separation of oil and grease from wastewater using the Option 6 technology will similarly optimize the removal of toxic organic pollutants amenable to this treatment technology. Consequently, EPA is effectively controlling toxic organics and other priority and nonconventional pollutant discharges in Oily Wastes Subcategory process wastewaters by regulating oil and grease ( as HEM).

In its analyses, EPA estimated that facilities will monitor once per month for oil and grease ( as HEM) and TSS. EPA expects that 12 data points for each pollutant per year will yield a meaningful basis for establishing compliance with the promulgated limitations through long term trends and short term variability in oil and grease ( as HEM) and TSS pollutant discharge loading patterns.

Although EPA is not changing the technology basis from that proposed, EPA is revising all of the proposed Oily Wastes Subcategory BPT limitations. This is a result of a recalculation of the limitations after EPA revised the data sets used to calculate the promulgated limitations to reflect changes including corrections and additional data ( see 67 FR 38754).

9 27 9.0  Technology Options 9.7.2 BCT In deciding whether to adopt more stringent limitations for BCT than BPT, EPA considered whether there are technologies that achieve greater removals of conventional pollutants than adopted for BPT, and whether those technologies are cost reasonable under the standards established by the CWA. EPA generally refers to the decision criteria as the   BCT cost test.  EPA is promulgating effluent limitations for conventional parameters ( e. g., pH, TSS, oil and grease) equivalent to BPT for this subcategory because it identified no technologies that can achieve greater removals of conventional pollutants than the selected BPT technology basis that also pass the BCT cost test. EPA evaluated the addition of ultrafiltration technology to the BPT technology basis as a means to obtain further oil and grease reductions. However, this technology option failed the BCT cost test. For a more detailed description of the BCT cost test and details on EPA s analysis, see Chapter 4 of the EEBA.

9.7.3 BAT EPA proposed to control toxic and nonconventional pollutants by establishing BAT limitations based on Option 6 technology. As described in Section 9.7.1, EPA has decided not to establish BAT toxic and nonconventional limitations based on the Option 6 technology. While the BPT limitations are cost reasonable, the additional costs associated with compliance with Option 6 generated BAT limitations are not warranted. EPA has determined that these costs, primarily monitoring costs, are not warranted in view of the small quantity of additional effluent reduction ( if any) the BAT limitations would produce. As explained above, EPA has determined that the BPT limitation on oil and grease ( as HEM) will effectively control toxic and nonconventional discharges in Oily Wastes Subcategory process wastewaters. EPA has not identified any more stringent economically achievable treatment technology option beyond BPT technology ( Option 6) that it considered to represent BAT level of control applicable to Oily Wastes Subcategory facilities.

For the reasons explained above, EPA has concluded that it should not establish BAT limitations for specific pollutant parameters for Oily Waste operations. EPA notes that permit writers retain the authority to establish, on a case by case basis under Section 301( b)( 1)( C) of the CWA, toxic effluent limitations that are necessary to meet state water quality standards.

9.7.4 NSPS EPA is promulgating NSPS that would control pH and the same conventional pollutants controlled at the BPT and BCT levels. The selected technology basis for NSPS for this subcategory for the final rule is Option 6. This is unchanged from the proposal. EPA projects no barrier to entry for new source direct dischargers associated with Option 6 because: ( 1) Option 6 technology is currently used at existing direct dischargers ( i. e., Option 6 technology is technically available), and ( 2) there is no barrier to entry for new sources.

9 28 9.0  Technology Options EPA evaluated the economic impacts for existing direct dischargers associated with compliance with limitations based on Option 6 and found Option 6 to be economically achievable ( no closures projected). EPA expects compliance costs to be lower for new sources as new sources can use Option 6 technology without incurring retrofitting costs ( as is required for some existing sources). Additionally, EPA projects no barrier to entry for Oily Wastes NSPS based on the Option 6 technology because approximately 97 percent of Oily Wastes direct dischargers have after tax compliance costs less than 1 percent of revenue and 3 percent have after tax compliance costs between 1 to 3 percent of revenue.

In addition, EPA also evaluated and rejected more stringent technology options for Oily Wastes NSPS ( i. e., Options 8 and 10). EPA reviewed its database for the Option 8 and 10 technologies and found that the database for Option 8 and 10 technologies is insufficient ( i. e., no available data) or the costs are not commensurate with the pollutant removals ( see 66 FR 457).

Consequently, EPA selected Option 6 technology as the basis for NSPS in the Oily Wastes Subcategory. See Section 11.0 for a description of how these new source compliance costs were developed and Chapter 9 of the EEBA for a description of the framework EPA used for the barrier to entry analysis and general discussion of the results.

In addition, EPA also evaluated and rejected more stringent technology options for Oily Wastes NSPS ( i. e., Options 8 and 10). EPA reviewed its database for the Option 8 and 10 technologies and found no available data for Option 8 and 10 technologies. Since EPA's database did not contain Option 10 treatability data from Oily Wastes facilities, EPA considered transferring limitations for Option 10 from the Shipbuilding Dry Dock or Railroad Line Maintenance Subcategories. EPA ultimately rejected this approach, however, because influent wastewaters in the Shipbuilding Dry Dock and Railroad Line Maintenance Subcategories are generally less concentrated and contain less pollutants than wastewaters discharged by Oily Wastes facilities.

9.7.5 PSES EPA evaluated the same technology options for indirect dischargers in the Oily Wastes Subcategory as for direct dischargers in the subcategory. For the final rule, EPA considered the same option as evaluated for BAT ( i. e., Option 6). EPA did not further evaluate Options 5, 7, and 8 for the final rule for the same reasons as explained for BPT above. See Sections 11.0 and 12.0 for the final estimated compliance costs and pollutant loadings for Option 6.

EPA proposed to establish PSES for existing indirect dischargers in the Oily Wastes Subcategory based on the Option 6 technology ( i. e., the same technology basis that is being promulgated for BPT/ BCT/ NSPS for this subcategory) with a   low flow  exclusion of 2 MGY to reduce economic impacts on small businesses and administrative burden for control authorities. Based on the revisions and corrections to the EPA Costs & Loadings Model 9 29 9.0  Technology Options discussed in the NODA, preamble to the final rule, and Sections 11.0 and 12.0, and previously discussed, EPA determined that the toxic pollutant reductions are very expensive in dollars per toxic pounds removed. The cost effectiveness value ( in 1981$) for Option 6 for indirect dischargers in the Oily Wastes Subcategory is in excess of $ 3,500/ PE removed. This suggests that the technology is not truly   available.  EPA has determined that Option 6 technology with a 2 MGY low flow cutoff is not the best available technology economically achievable for existing indirect dischargers in the Oily Wastes Subcategory. Therefore, EPA is not establishing PSES for this subcategory based on Option 6 technology with a 2 MGY low flow cutoff.

As discussed in the June 2002 NODA ( 67 FR 38804), EPA also considered alternative options for which economic impacts could be less costly than Option 6 technology with a 2 MGY low flow cutoff. These options potentially have compliance costs more closely aligned with toxic pollutant reductions. EPA considered the following alternative options for the final rule:

  Option A: No regulation; and   Option B: Option 6 with a higher low flow exclusion.

As discussed in the NODA, preamble to the final rule, and Sections 11.0 and 12.0, based on comments, EPA has revised its methodology for estimating compliance costs and pollutant loadings for Option 6 with a higher low flow exclusion ( Option B). Using information from this revised analysis, EPA concludes that none of the alternative low flow exclusions ( even as high as 6.25 MGY) represented   available technology  because the costs associated with these alternatives were not commensurate with the projected toxic pollutants reductions. Therefore, EPA is not establishing PSES for existing indirect dischargers in the Oily Wastes Subcategory ( Option A). Since EPA did not identify another technology basis that was more cost effective, EPA is not promulgating PSES for existing indirect dischargers in the Oily Wastes Subcategory. These facilities remain subject to the General Pretreatment Standards ( 40 CFR 403) and local limits, as applicable.

9.7.6 PSNS EPA proposed to establish PSNS for indirect dischargers in the Oily Wastes Subcategory based on the Option 6 technology ( i. e., the same technology basis that is being promulgated for NSPS for this subcategory) with a   low flow  exclusion of 2 MGY to reduce economic impacts on small businesses and reduce administrative burden to POTWs.

For the final rule, EPA evaluated setting Oily Wastes PSNS based on Option 6 technology and assessed the financial burden of Oily Wastes PSNS based on Option 6 technology on new Oily Wastes indirect dischargers. Specifically, EPA's   barrier to entry' analysis identified whether Oily Wastes PSNS based on Option 6 technology would pose sufficient financial burden on new Oily Wastes facilities to constitute a material barrier to entry into the MP& M Point Source Category.

9 30 9.0  Technology Options EPA projects a barrier to entry for Oily Waste PSNS based on Option 6 technology as approximately because 1 percent of Oily Waste indirect dischargers have after tax compliance costs between 1 to 3 percent of revenue and 5 percent have after tax compliance costs between 3 to 5 percent of revenue. Consequently, EPA rejected Option 6 technology as the basis for PSNS in the Oily Wastes Subcategory. EPA has selected   no further regulation  for new Oily Wastes indirect dischargers and is not revising PSNS for new Oily Wastes indirect dischargers. Wastewater discharges to POTWs from facilities in this subcategory will remain regulated by local limits and General Pretreatment Standards ( Part 403), as applicable. See Section 11.0 for a description of how these new source compliance costs were developed and Chapter 9 of the EEBA for a description of the framework EPA used for the barrier to entry analysis and general discussion of the results.

Railroad Line Maintenance Subcategory EPA is not establishing limitations or standards for any facilities that would have been subject to this subcategory. Permit writers and control authorities will establish controls using BPJ to regulate wastewater discharges from these facilities.

9.8.1 BPT At proposal, EPA evaluated four technology options for the Railroad Line Maintenance ( RRLM) Subcategory. These included Options 7 and 8, which are described in detail in Section 9.7.1, and Options 9 and 10, described below. In addition, for the final rule, EPA evaluated Option 6 for this subcategory ( see Section 9.7.1).

Option 9 Option 9 consists of end of pipe chemical emulsion breaking followed by dissolved air flotation ( DAF) to remove flocculated oils. This treatment train is demonstrated in both the Shipbuilding Dry Dock and RRLM Subcategories and effectively removes emulsified oils and suspended solids. Option 9 also includes contract hauling of organic solvent bearing wastewater instead of discharge.

Option 10 Option 10 consists of the end of pipe treatment technologies included in Option 9 plus in process flow control and pollution prevention technologies, which allow for recovery and reuse of materials along with water conservation. The specific Option 10 in process technologies include:

  Two stage countercurrent cascade rinsing for all flowing rinses;

  Centrifugation and recycling of painting water curtains; and 9 31 9.8 9.0  Technology Options   Centrifugation, pasteurization, and recycling of water soluble machining coolants.

Option Selection For the final rule, EPA evaluated setting BPT limitations for two pollutants, TSS and oil and grease ( as HEM), for direct dischargers in the RRLM Subcategory based on a different technology basis from that proposed in 2001. EPA proposed Option 10 technology as the technology basis for BPT. However, as discussed in the NODA, EPA considered promulgating limitations for the final rule based on the Option 6 technology for the RRLM Subcategory ( see 67 FR 38804). Option 6 technology includes the following: ( 1) in process flow control and pollution prevention; and ( 2) oil/ water separation by chemical emulsion breaking and skimming ( see Section 9.7.1 for additional details on the Option 6 technology).

For the RRLM Subcategory, EPA changed the technology basis considered for the final rule based on comments and data submitted by the American Association of Railroads ( AAR). This organization is a trade association that currently represents all facilities in this subcategory. As discussed in the NODA ( 67 FR 38755), for each RRLM direct discharging facility known to them, AAR provided current permit limits, treatment in place, and summarized information on each facility s measured monthly average and daily maximum values. AAR also provided a year s worth of long term monitoring data for each facility ( see Section 15.1 of the rulemaking record for the AAR surveys). This data shows that, contrary to EPA s initial findings in the 2001 proposal, most RRLM direct dischargers treat their wastewater by chemical emulsion breaking/ oil skimming ( Option 6). Based on this updated information, EPA rejected Option 10 as the technology basis for BPT. The 2001 proposal also contains detailed discussions on why EPA rejected BPT limitations based on other BPT technology options ( see 66 FR 451). The information in the rulemaking record provides no basis for EPA to change this conclusion.

As previously discussed, after publication of the June 2002 NODA, EPA also conducted another review of all RRLM facilities in the MP& M survey database to determine the destination of discharged wastewater ( i. e., either directly to surface waters or indirectly to POTWs or both) and the applicability of the final rule to discharged wastewaters. As a result of this review, EPA determined that its survey database did not accurately represent direct dischargers in this subcategory. Consequently, for the final rule, EPA used the information supplied by AAR as a basis for its analyses and conclusions on direct dischargers in this subcategory.

AAR provided information on 27 facilities. EPA reviewed the information on each of these facilities to ensure they were direct dischargers, discharged wastewaters resulting from operations subject to this final rule, and discharged " process" wastewaters as defined by the final rule. As a result of this review, EPA concluded that 18 of the facilities for which AAR provided information do not directly discharge wastewaters exclusively from oily operations ( see Section V. A of the preamble to the final rule). Therefore, EPA's final database consists of data for nine direct discharging RRLM facilities. EPA considered promulgating BPT limitations for 9 32 9.0  Technology Options these nine direct discharging RRLM facilities based on the Option 6 technology. The Agency made the following conclusions during its evaluation of Option 6 for this subcategory.

First, this technology is readily applicable to all facilities in the RRLM Subcategory. All direct dischargers in the RRLM Subcategory currently use wastewater treatment equivalent or better than chemical emulsion breaking/ oil skimming ( Option 6). Second, EPA estimates that compliance with BPT limitations based on Option 6 technology will result in no closures of the existing direct dischargers in the RRLM Subcategory. Moreover, none of the facilities identified by AAR are small businesses as defined by the Small Business Administration ( SBA). Third, most of the RRLM facilities identified by AAR have NPDES daily maximum permit limitations for oil and grease ( as HEM) and TSS as 15 and 45 mg/ L, respectively. Based on AAR survey information, EPA concludes that these oil and grease ( as HEM) and TSS daily maximum limits represent the average of the best performances of facilities utilizing Option 6 technology.

EPA evaluated the compliance costs and load reductions associated with establishing BPT daily maximum limitations equivalent to 15 and 45 mg/ L for oil and grease ( as HEM) and TSS, respectively. EPA concluded that all of the facilities identified by AAR currently meet a daily maximum oil and grease limit of 15 mg/ L and most currently monitor once per month. Therefore, EPA estimates no pollutant load reductions and minimal incremental annualized compliance costs for the monitoring associated with a BPT daily maximum limitation equivalent to 15 mg/ L for oil and grease ( as HEM). For TSS, with the exception of one facility, all RRLM facilities identified by AAR currently meet a daily maximum limit of 45 mg/ L. For this one facility, EPA estimates the TSS pollutant loadings reductions associated with a BPT daily maximum limitation equivalent to 45 mg/ L to be less than 1 pound of TSS per day. Given the fact that the few facilities in this subcategory are already essentially achieving the limitations under consideration, EPA has determined that additional national regulation is not warranted. As a result of this analysis, EPA concludes that it is more appropriate to address permits limitations for this industry on a case by case basis and that additional national regulation of direct discharges in the RRLM Subcategory at this time is unwarranted.

9.8.2 BCT In deciding whether to adopt more stringent limitations for BCT than BPT, EPA considers whether there are technologies that achieve greater removals of conventional pollutants than adopted for BPT, and whether those technologies are cost reasonable under the standards established by the CWA. EPA generally refers to the decision criteria as the   BCT cost test.  For a more detailed description of the BCT cost test and details of EPA s analysis, see Chapter 4 of the EEBA.

For the reasons discussed above, EPA is not establishing BCT limitations for the RRLM Subcategory.

9 33 9.0  Technology Options 9.8.3 BAT As proposed, EPA is not establishing BAT regulations for the RRLM Subcategory. EPA did not propose BAT regulations because the Agency concluded that facilities in this subcategory discharge very few pounds of toxic pollutants. EPA estimates that six facilities discharge 34 PE per year to surface waters, or about 6 PE per year per facility. The Agency based the loadings calculations on EPA sampling data, which found very few priority toxic pollutants at treatable levels in raw wastewater. EPA has received no data or information during the rulemaking that contradicts these conclusions. Therefore, nationally applicable regulations for toxic and nonconventional pollutants are unnecessary at this time and direct dischargers will remain subject to permit limitations for toxic and nonconventional pollutants established on a case by case basis using BPJ.

9.8.4 NSPS EPA proposed setting NSPS based on Option 10 technology for this subcategory. For the final rule, EPA considered setting RRLM NSPS based on Option 10 technology and assessed the financial burden of RRLM NSPS based on Option 10 technology on new RRLM direct dischargers. Specifically, EPA s   barrier to entry  analysis identified whether RRLM NSPS based on Option 10 technology would pose sufficient financial burden as to constitute a material barrier to entry into the MP& M Point Source Category.

EPA projects no barrier to entry for RRLM NSPS based on Option 10 technology because: ( 1) Option 10 technology is currently used at existing RRLM direct dischargers ( i. e., Option 10 technology is technically available), and ( 2) all RRLM direct dischargers have new source compliance costs that are less than 1 percent of revenue. However, EPA is not promulgating RRLM NSPS based on the Option 10 technology because EPA concludes that it is more appropriate to address limitations for this industry on a case by case basis and that national regulation of direct discharges in the RRLM Subcategory at this time is unwarranted. See Section 11.0 for a description of how these new source compliance costs were developed and Chapter 9 of the EEBA for a description of the framework EPA used for the barrier to entry analysis and general discussion of the results.

9.8.5 PSES and PSNS EPA proposed not to establish pretreatment standards for existing and new indirect dischargers in the RRLM Subcategory based on the small quantity of toxic pollutants discharged to the environment ( after POTW treatment) by facilities in this subcategory ( i. e., approximately 2 PE removed annually per facility ( see 66 FR 470 471)). For the same reasons set out in the 2001 proposal, EPA is not promulgating pretreatment standards for existing or new indirect dischargers in this subcategory. These facilities remain subject to the General Pretreatment Standards ( 40 CFR 403) and local limits.

9 34 9.0  Technology Options 9.9 Shipbuilding Dry Dock Subcategory EPA is not establishing limitations or standards for any facilities that would have been subject to this subcategory. Permit writers and control authorities will establish controls using BPJ to regulate wastewater discharges from these facilities.

9.9.1 BPT/ BCT/ BAT/ NSPS EPA evaluated four technology options for the Shipbuilding Dry Dock ( SDD) Subcategory. These include Options 7 and 8, which are described in detail in Section 9.7.1, and Options 9 and 10, which are described in detail in Section 9.8.1.

As discussed in the 2001 proposal ( 66 FR 451), EPA dropped Options 7 and 9 from further consideration because Options 8 and 10, respectively, cost less and provided greater pollutant removals. EPA also evaluated and rejected a more stringent technology option for SDD NSPS ( i. e., Option 8). EPA reviewed its database for the Option 8 technology and found that no available data or possibility of data transfer from the other oily subcategories are available because ultrafiltration does not consistently show a better removal than Option 10 to support a determination that NSPS based on Option 8 standards are technically achievable. EPA concluded that Option 8 does not represent the best practicable control technology. Therefore, for the final rule, EPA considered only Option 10 as the basis for limitations for the SDD Subcategory. See Sections 11.0 and 12.0 for the final estimated compliance costs and pollutant loadings for Option 10.

At the time of the 2001 proposal, EPA identified six direct discharging SDD facilities with multiple discharges. Based on the information in the database at that time, discharges from these facilities contained minimal concentrations of toxic organic and metals pollutants (< 9 PE/ facility), but substantial quantities of conventional pollutants, particularly oil and grease. Consequently, EPA proposed to establish BPT limitations and NSPS for only two pollutants, TSS and oil and grease ( as HEM), for direct dischargers in the SDD Subcategory based on Option 10 technology. This technology includes the following: ( 1) in process flow control and pollution prevention, and ( 2) oil/ water separation by chemical emulsion breaking and oil/ water separation by dissolved air flotation ( see Section 9.8.1). EPA proposed this technology basis because some existing SDD facilities use this technology and it projected significant reductions in conventional pollutants and determined that these reductions were cost reasonable.

Following proposal, EPA received comments and supporting data indicating that its estimates of current pollutant discharges from this subcategory were overestimated. In particular, commentors claimed that current discharges of oil and grease were minimal and that national regulation was not warranted for this subcategory.

For the final rule, EPA incorporated the additional information provided by commentors into its analysis. EPA continues to conclude that there are six direct discharging SDD facilities. However, EPA now concludes that direct discharges from these facilities 9 35 9.0  Technology Options generally contain minimal levels of all pollutants. In particular, EPA s database indicates that regulation of oil and grease in direct discharges from SDD facilities is unwarranted because current oil and grease discharges from these facilities are not detectable (< 5 mg/ L) or nearly not detectable. EPA has similarly determined that it should not establish nationally applicable limitations and standards for TSS because TSS discharges are, on average, minimal. The data show that TSS discharges may increase episodically, particularly when the dry dock is performing abrasive blasting operations cleaning. However, EPA has concluded that these episodic discharges from six facilities do not warrant national regulation.

Therefore, nationally applicable regulations for new and existing SDD direct dischargers are unnecessary at this time and these facilities will remain subject to permit limitations established on a case by case basis using BPJ.

9.9.2 PSES and PSNS EPA proposed not to establish pretreatment standards for existing and new indirect dischargers in the SDD Subcategory based on the small number of facilities in this subcategory and on the small quantity of toxic pollutants removed by the technology options evaluated by EPA at proposal ( i. e., less than 26 PE removed annually per facility ( see 66 FR 471)). For the same reasons set out in the 2001 proposal, EPA is not promulgating pretreatment standards for existing or new indirect dischargers in this subcategory. These facilities remain subject to the General Pretreatment Standards ( 40 CFR 403) and local limits.

9.10 Summary of Technology Options Considered and Selected for the Final MP& M Rule Table 9 1 summarizes all of the technology options considered for the MP& M subcategories for either the proposed or final rules. Table 9 2 summarizes EPA s selected technology bases for the final rule.

9 36 9.0  Technology Options 9 37 Table 9 1 Technology Options by Subcategory Treatment or Source Reduction Technology Technology Options Considered for the General Metals, Metal Finishing Job Shops, Printed Wiring Board, Steel Forming and Finishing, and Non

Chromium Anodizing Subcategoriesa Technology Options Considered for the Oily Wastes, Shipbuilding Dry Dock, and Railroad Line Maintenance Subcategoriesb 1 2 2S 3 4 413 to 433 Upgrade Local Limits to 433 Upgrade 5 6 7 8 9 10 Chemical Precipitation               Gravity Clarification for Metal Hydroxide Removal           Microfiltration for Metal Hydroxide Removal     Chemical Emulsion Breaking Followed by Gravity Separation for Oil Removal               Ultrafiltration for Oil Removal         Chemical Emulsion Breaking Followed by Dissolved Air Flotation for Oil Removal     Alkaline Chlorination for Cyanide Removal               Chemical Reduction of Hexavalent Chromium               Chelation Breaking/ Precipitation to Remove Complexed Metals               Contract Hauling of Organic Solvent Bearing Wastewater Instead of Discharge                           Countercurrent Cascade Rinsing to Conserve Water             Centrifugation of Painting Water Curtains to Extend Life             Centrifugation and Pasteurization of Machining Coolants to Extend Life             Sand Filter to Remove Additional Suspended Solids   Sludge Dewatering and Disposal                   aSee Section 9.2.2 for a discussion of BCT options considered for the General Metals Subcategory.