Economic Analysis for Proposal of Certain Federal Water Quality Standards Applicable to Maine

                                                Contract # EP-BPA-13-W-0001

                                                March 24, 2016

                                                Prepared for:
                                                United States Environmental Protection Agency
                                                Region 1
                                                5 Post Office Square, Suite 100 (OEP06-2)
                                                Boston, MA 02109

                                                Submitted by:
                                                Abt Associates
                                                55 Wheeler Street
Cambridge, MA 02138

                                                Under Subcontract to:
                                                WaterVision LLC

Executive Summary
The United States Environmental Protection Agency (EPA) is proposing water quality standards (WQS) applicable to waters under jurisdiction of the State of Maine. The proposal addresses EPA's disapproval of many of the state's human health criteria (HHC) and six other criteria for waters in Indian lands, as well as the disapproval of three criteria and standards affecting all state waters. The proposal also addresses an Administrator's determination that many of Maine's HHC are not adequate to protect the designated use of sustenance fishing.
Although the proposed rule does not establish any requirements directly applicable to regulated entities or other sources of pollution, state implementation may result in new or revised Maine Pollutant Discharge Elimination System (MEPDES) permit conditions for point source dischargers and additional controls on nonpoint sources of pollutant loadings. This report provides estimates of the potential incremental compliance actions and costs that may be associated with the proposed regulation.
The analysis focuses on the costs only and does not quantify benefits that may result from the proposed WQS, including for example, avoided adverse health impacts and associated costs from cleaner waters and positive impacts to the tourism, fishing, or shellfishing industries.
EPA used available data from water quality assessments, permit fact sheets, priority pollutant scans, and other sources to evaluate the potential effects of, and resultant costs of the action. Based on the available information, EPA determined that the proposed criteria for pH and temperature (for waters in Indian lands), proposed criteria for dissolved oxygen (DO) (for all Class A state waters) and proposed criteria for phenol (for waters outside of Indian lands) are unlikely to result in incremental costs to point sources. EPA estimated the potential costs to point sources resulting from proposed HHC, bacteria criteria, ammonia criteria, and mixing zone policy for waters in Indian lands. Exhibit E- 1 summarizes these costs.
Low-cost pollution prevention (P2) strategies would result in far lower costs than end-of-pipe treatment, which would be used only if less expensive approaches were unsuccessful. Total annualized costs range from $213,000 if lower-cost options are effective to a worst-case estimate of $1 million if end-of-pipe treatment is needed. EPA notes that these annual costs are well below the threshold of $100 million that triggers more extensive economic analysis (e.g., a complete benefit-cost analysis) under Executive Orders 12866 and 13563.
Exhibit E- 1. Summary of Estimated Costs for the Proposed Rule[1]
Proposed WQS
Annualized Costs
(thousands; 2014$)[2]
Human health criteria for waters in Indian lands
$28

$43
Bacteria criteria for waters in Indian lands
$185

$705
Mixing zone policy for waters in Indian lands
Not estimated

$273
Total[3]
$213

$1,021
1. Excludes costs for proposed ammonia criteria, for which EPA expects costs to be zero. See Section 4.3.
2. Except as otherwise noted (see Section 4.4 for assumptions regarding expected useful life of cooling towers), one-time costs are annualized over 20 years using a 3 percent discount rate. See Appendix E for results using a 7 percent discount rate.
3. Lower bound of total costs excludes costs associated with mixing zone policy for which EPA estimated only the upper bound scenario. See Section 4.4 for details.

While the analysis of costs generally follows the approach a permit writer would use to evaluate and set discharge permit conditions, reliance on available data involves uncertainty and limitations not present during actual permit development, when the permit writer may have access to and incorporate more site-specific data (e.g., ambient water quality samples, priority pollutant scans using lower detection limits). See Section 6.3 for further discussion of the uncertainty associated with the use of existing data.

Contents
Executive Summary	ii
Contents	i
Exhibits	v
List of Abbreviations	viii
1	Introduction	1
1.1	Background	1
1.2	Purpose and Scope of the Analysis	4
1.2.1	Proposed WQS Applicable only to Waters in Indian Lands	5
1.2.2	Proposed Criteria Applicable to All State Waters (DO) and to Waters Outside of Indian Lands (Phenol)	6
1.3	Organization of Report	7
2	Baseline for the Analysis	9
2.1	Sources of Pollutants to Surface Waters	9
2.1.1	Municipal and Industrial Dischargers	9
2.1.2	Urban Stormwater	10
2.1.3	Onsite Wastewater Disposal Systems	11
2.1.4	Agriculture and Forestry	12
2.1.5	Atmospheric Deposition	12
2.1.6	Contaminated Sediments	13
2.2	Baseline Water Quality and Criteria	13
2.2.1	Water Quality Impairments	13
2.2.2	Toxics	15
2.2.3	Bacteria	19
2.2.4	Ammonia	20
2.2.5	pH	21
2.2.6	Tidal Temperature	21
2.2.7	Mixing Zone	21
2.2.8	Dissolved Oxygen	22
3	Proposed Criteria	24
3.1	Proposed Criteria for Waters in Indian Lands	24
3.1.1	Human Health Criteria	24
3.1.2	Bacteria	28
3.1.3	Ammonia	31
3.1.4	pH	34
3.1.5	Temperature Criterion for Tidal Waters	34
3.1.6	Mixing Zone	35
3.2	Proposed Dissolved Oxygen Criteria for All State Waters	37
3.3	Proposed Phenol Criteria for State Waters Outside of Indian Lands	38
4	Method for Estimating Potential Costs: Point Sources	40
4.1	Costs from Proposed Human Health Criteria for Waters in Indian Lands	40
4.1.1	Dischargers to Waters in Indian Lands or Tributaries	41
4.1.2	Reasonable Potential Analysis	43
4.1.3	Projecting Effluent Limitations	48
4.1.4	Identifying Compliance Scenarios and Costs	49
4.2	Costs from Proposed Bacteria Criteria for Waters in Indian Lands	53
4.3	Costs from Proposed Ammonia Criteria for Waters in Indian Lands	55
4.4	Costs from the Proposed Mixing Zone Policy	58
5	Methods for Identifying Potential Costs: Nonpoint Sources	60
5.1	Identifying Exceedances	60
5.2	Identifying Compliance Actions and Costs	60
6	Potential Compliance Costs	62
6.1	Point Sources	62
6.2	Nonpoint Sources	64
6.3	Uncertainties and Quality Assurance	64
7	References	67
A	Facility-level Analyses of Implication of Proposed Human Health and Ammonia Criteria	70
A.1	Baileyville POTW	70
A.1.1	Effluent Data	70
A.1.2	Reasonable Potential Analysis	71
A.2	Brownville	72
A.3	Calais POTW	72
A.3.1	Effluent Data	73
A.3.2	Reasonable Potential Analysis	73
A.4	Calais School	74
A.5	Cobb State Fish Hatchery	74
A.6	Covanta Maine	75
A.7	Dolby Hydro Project	75
A.8	Dover-Foxcroft Water District	75
A.9	Dover-Foxcroft WWTP	76
A.9.1	Effluent Data	76
A.9.2	Reasonable Potential Analysis	76
A.10	East Millinocket Hydro Project	78
A.11	East Millinocket POTW	78
A.12	Eustis Hydro Project	78
A.13	Grand Lake Stream Fish Hatchery	79
A.14	Guilford-Sangerville WWTF	79
A.14.1	Effluent Data	80
A.14.2	Reasonable Potential Analysis	80
A.15	Houlton Water Company POTW	81
A.15.1	Effluent Data	81
A.15.2	Reasonable Potential Analysis	82
A.16	Howland Hydro	83
A.17	Howland POTW	83
A.17.1	Effluent Data	83
A.17.2	Reasonable Potential Analysis	83
A.18	Lincoln Sanitary District	84
A.18.1	Effluent Data	85
A.18.2	Reasonable Potential Analysis	85
A.19	Mattaceunk Hydro Project	86
A.20	Mattawamkeag WWTF	86
A.21	Milford	86
A.22	Millinocket Hydro	87
A.23	Millinocket POTW	87
A.23.1	Effluent Data	87
A.23.2	Reasonable Potential Analysis	87
A.24	Milo POTW	88
A.24.1	Effluent Data	88
A.24.2	Reasonable Potential Analysis	89
A.25	Passamaquoddy POTW	90
A.26	Passamaquoddy Water District	90
A.27	Penobscot Indian Nation	90
A.27.1	Effluent Data	90
A.27.2	Reasonable Potential Analysis	91
A.28	Tate and Lyle Ingredients	91
A.28.1	Effluent Data	92
A.28.2	Reasonable Potential Analysis	92
A.28.3	Effluent Limitations	93
A.28.4	Compliance Costs	94
A.29	Washington County Community College	97
A.30	West Enfield Hydro	97
A.31	Woodland Hydro	97
A.32	Woodland Pulp	98
A.32.1	Effluent Data	98
A.32.2	Reasonable Potential Analysis	98
A.33	Woodland Pulp: North Site	99
B	Derivation of Mercury Water Column Concentration for Use in Evaluating Reasonable Potential	100
C	Estimated Flows for Selected Receiving Waters in Indian Lands	102
C.1	Harmonic Mean Flow	102
C.2	Dissolved Concentration Potential	102
D	Review of pH Limitations in Existing Permits and Cost Potential	104
D.1	Calais POTW	104
D.2	Guilford-Sangerville	104
D.3	Houlton WWTF	105
D.4	Lincoln Sanitary District	105
D.5	Tate and Lyle	105
D.6	Woodland Pulp	106
E	Potential Point Source Compliance Costs, 7% Discount Rate	107

Exhibits
Exhibit E- 1. Summary of Estimated Costs for the Proposed Rule[1]	iii
Exhibit 1-1. EPA Disapprovals of Maine WQS and Proposed WQS	3
Exhibit 1-2: Indian lands in Maine and location of facilities with permits to discharge to waters in Indian lands or tributaries.	6
Exhibit 1-3. Document Roadmap for Analysis of Effects and Costs of EPA Proposed Rules in Response to EPA Disapprovals[1]	8
Exhibit 2-1. Number of Dischargers in Maine, by Category	9
Exhibit 2-2. Cumulative Size of Impaired Waters by Listing Cause/Stressor Type	14
Exhibit 2-3. Baseline Water Quality Criteria for Toxic Priority Pollutants in Maine[1]	16
Exhibit 3-1. Proposed Human Health Criteria for the Consumption of Water and Organisms and Organisms Only (ug/L)	24
Exhibit 3-2. Baseline and Proposed Bacteria Criteria	30
Exhibit 3-3. Comparison of Maine's baseline (solid line) and EPA's proposed (dashed lines) ammonia acute criteria for different temperatures[1]	32
Exhibit 3-4. Comparison of Maine's baseline (solid lines) and EPA's proposed (dashed lines) ammonia chronic criteria for different water temperatures.	33
Exhibit 3-5. Discharger with Thermal Mixing Zone Affecting Waters in Indian Lands	37
Exhibit 4-1. Summary of Dischargers to Waters in Indian Lands or Their Tributaries	41
Exhibit 4-2: Facilities discharging to the Penobscot River in Indian lands or its tributaries.	46
Exhibit 4-3. Summary of Dischargers with Detected Effluent Data and Reasonable Potential Analysis	47
Exhibit 4-4. Summary of Current Disinfection and Dechlorination Practices at Facilities with Bacteria Limitations	53
Exhibit 4-5. Summary of Ammonia Effluent Data	56
Exhibit 4-6. Summary of Ammonia Reasonable Potential Analysis	57
Exhibit 4-7. Estimates of Cooling Tower Retrofit Costs at Facility with Thermal Mixing Zone for Discharges to Waters in Indian Lands or Tributaries	59
Exhibit 6-1. Summary of Estimated Compliance Costs for Proposed Human Health Criteria for Waters in Indian Lands[1]	62
Exhibit 6-2. Summary of Estimated Compliance Costs for Proposed Criteria for Bacteria[1]	63
Exhibit 6-3. Summary of Upper Bound Estimated of Compliance Costs for Proposed Mixing Zone Policy[1]	63
Exhibit 6-4. Summary of Estimated Point Source Compliance Costs[1]	64
Exhibit 6-5. Uncertainties in Analysis of Costs	65
Exhibit A-1. Summary of Effluent Data: Baileyville POTW	71
Exhibit A-2. Mercury Load Allocation for St. Croix River and Passamaquoddy Bay	71
Exhibit A-3. Reasonable Potential Analysis for Baileyville POTW	72
Exhibit A-4. Summary of Effluent Data: Calais POTW	73
Exhibit A-5. Reasonable Potential Analysis for Calais POTW	74
Exhibit A-6. Outfall Data for Covanta Maine Facility[1]	75
Exhibit A-7. Summary of Effluent Data: Dover-Foxcroft WWTP	76
Exhibit A-8. Mercury Load Allocation for Penobscot River (Piscataquis Confluence)	77
Exhibit A-9. Mercury Load Allocation for Penobscot River, Downstream	77
Exhibit A-10. Reasonable Potential Analysis for Dover-Foxcroft WWTP	78
Exhibit A-11. Summary of Flow and Limitation Tiers: Guilford-Sangerville WWTF[1]	79
Exhibit A-12. Summary of Effluent Data: Guilford-Sangerville WWTF	80
Exhibit A-13. Reasonable Potential Analysis for Guilford-Sangerville WWTF	81
Exhibit A-14. Summary of Effluent Data: Houlton POTW	81
Exhibit A-15. Mercury Load Allocation for Meduxnekeag River	82
Exhibit A-16. Reasonable Potential Analysis for Houlton POTW	82
Exhibit A-17. Summary of Effluent Data: Howland POTW	83
Exhibit A-18. Mercury Load Allocation for Penobscot River at Howland POTW	84
Exhibit A-19. Reasonable Potential Analysis for Howland POTW	84
Exhibit A-20. Summary of Effluent Data: Lincoln Sanitary District	85
Exhibit A-21. Mercury Load Allocation for Penobscot River at Lincoln Sanitary District	85
Exhibit A-22. Reasonable Potential Analysis for Lincoln Sanitary District	86
Exhibit A-23. Summary of Effluent Data: Millinocket POTW	87
Exhibit A-24. Reasonable Potential Analysis for Millinocket POTW	88
Exhibit A-25. Summary of Effluent Data: Milo POTW	89
Exhibit A-26. Reasonable Potential Analysis for Milo POTW	89
Exhibit A-27. Summary of Effluent Data: Penobscot Indian Nation	91
Exhibit A-28. Reasonable Potential Analysis for Penobscot Indian Nation	91
Exhibit A-29. Summary of Effluent Data: Tate and Lyle	92
Exhibit A-30. Reasonable Potential Analysis for Tate and Lyle Ingredients	93
Exhibit A-31. Load Allocation for Tate and Lyle Ingredients	93
Exhibit A-32. Effluent Limitations for Tate and Lyle Ingredients	94
Exhibit A-33. Input Parameters Used to Estimate Granular Activated Carbon Treatment Costs for Tate and Lyle Ingredients	95
Exhibit A-34. Range of Compliance Costs for Bis(2-ethylhexyl)phthalate for Tate and Lyle Ingredients	96
Exhibit A-35. Summary of Effluent Data: Woodland Pulp	98
Exhibit A-36. Reasonable Potential Analysis for Woodland Pulp	99
Exhibit C- 1. Flow Statistics for Selected Receiving Waters in Indian Lands.	102
Exhibit E-1. Summary of Estimated Compliance Costs for Proposed Human Health Criteria for Waters in Indian Lands[1]	107
Exhibit E-2. Summary of Estimated Compliance Costs for Proposed Criteria for Bacteria[1]	107
Exhibit E-3. Summary of Upper Bound Estimated of Compliance Costs for Proposed Mixing Zone Policy[1]	108
Exhibit E-4. Summary of Estimated Point Source Compliance Costs[1]	108

List of Abbreviations
AMEL			Average monthly effluent limitation
BMP			Best management practice
CCC			Criterion continuous concentration
CMC			Criterion maximum concentration
CPI			Consumer Price Index
CWA		 	Clean Water Act
DCP			Dissolved concentration potential
DDT			Dichlorodiphenyltrichloroethane
DMR			Discharge monitoring report
DO				Dissolved oxygen
ENR CCI		Engineering News-Record construction cost index
EPA			United States Environmental Protection Agency
FCR			Fish consumption rate
GAC			Granular activated carbon
GDP-IPD 		Gross Domestic Product implicit price deflator
HHC			Human health criteria
I&I				Inflow and infiltration
ICIS			Integrated Compliance Information System
LID			Low impact development
MDIFW		Maine Department of Inland Fisheries and Wildlife
MEDEA		Maine Division of Environmental and Assessment
MEDEH		Maine Division of Environmental Health
MEC			Maximum effluent concentration
MEDEP		Maine Department of Environmental Protection
MEPDES		Maine Pollutant Discharge Elimination System
MPN			Most probable number
MS4			Municipal separate storm sewer systems
NOI			Notice of intent
NPDES		National Pollutant Discharge Elimination System
O&M			Operation and Maintenance
OSDS			Onsite Wastewater Disposal Systems
P2				Pollution prevention
PCB			Polychlorinated biphenyl
POTW			Publicly owned treatment works
PPI				Producer Price Index
Ppm			parts per million
SIC			Standard industrial classification
SU				Standard units
SWMP			Stormwater management program
TMDL			Total maximum daily load
WDL			Waste Discharge License
WQBELs		Water quality based effluent limitations
WQS			Water quality standards
WWTF		Wastewater treatment facility
ZID			Zone of initial dilution
Introduction
The United States Environmental Protection Agency (EPA) is proposing water quality standards (WQS) applicable to waters under jurisdiction of the State of Maine. The proposal addresses EPA's disapproval of many of the state's human health criteria (HHC) and six other criteria for waters in Indian lands, as well as the disapproval of three criteria and standards affecting all state waters. The proposal also addresses an Administrator's determination that many of Maine's HHC are not adequate to protect the designated use of sustenance fishing. This report provides estimates of the potential incremental compliance actions and costs that may be associated with the proposed regulations.
For the purposes of this report, the term "waters in Indian lands" refers to waters in the reservations and trust lands of the four Indian tribes in Maine, as described more fully in the preamble to the proposed rule and in EPA's Technical Support Document, entitled "Scope of Waters"; and "discharges to waters in Indian lands and their tributaries" refers to discharges directly into waters in Indian lands, discharges indirectly to such waters where the point of discharge is upstream of the boundary of the Indian lands, and discharges to the tributaries of such waters.
Background
The Federal Water Pollution Control Act (as amended through P.L. 107 - 303, November 27, 2002), also known as the Clean Water Act (CWA), sets the basic structure for regulating pollutant discharges into the waters of the United States. In the CWA, Congress established the national objective to "restore and maintain the chemical, physical, and biological integrity of the Nation's waters," and to achieve "wherever attainable, an interim goal of water quality which provides for the protection and propagation of fish, shellfish, and wildlife and for recreation in and on the water" (CWA sections 101(a) and 101(a)(2)).
The CWA establishes the basis for the current WQS regulation and program. CWA section 303 addresses the development of state and authorized tribal WQS. WQS reflect the CWA national objectives for each water body. The core components of these standards are designated uses, water quality criteria, and antidegradation requirements. Designated uses establish the environmental objectives for a water body, while water quality criteria define the conditions necessary to achieve those environmental objectives. The antidegradation program complements designated uses and criteria by providing a framework for maintaining and protecting water quality.
After states, authorized tribes, territories, and the District of Columbia (hereafter, states and authorized tribes) designate the uses of waters under their jurisdiction, they must establish water quality criteria that protect those designated uses. EPA's regulation at §131.11(a)(1) provides that such criteria "must be based on sound scientific rationale, and must contain sufficient parameters or constituents to protect the designated use." States and authorized tribes must also adopt antidegradation policies to protect and maintain high quality waters and existing uses of all waters, and identify specific methods to implement those policies (§131.12).
Any new or revised WQS adopted by a state under CWA section 303(c) must be submitted to EPA for review, to determine whether it meets the CWA's requirements, and approval or disapproval. If EPA disapproves a state WQS, EPA is required, under CWA section 303(c)(4), to promptly propose federal WQS if the state does not adequately address the disapproval within ninety (90) days after any disapproval. EPA is further required to promulgate a federal standard within ninety days of the proposal unless the state adopts a revised standard that meets the requirements of the CWA.
CWA section 303(c)(4)(B) authorizes the Administrator to determine, even in the absence of a state submission, that a new or revised standard is necessary to meet CWA requirements. Upon making such a determination, EPA shall promptly propose, and then within ninety days promulgate, any such new or revised standard unless prior to such promulgation, the state has adopted a revised or new WQS which EPA determines to be in accordance with the CWA.
Exhibit 1-1 summarizes the proposed WQS associated with EPA's disapprovals of Maine WQS. Items 1 through 7 in the table apply specifically to waters in Indian lands, whereas Items 8 through 10 apply more broadly to all state waters, unless otherwise specified. In addition, with respect to item 1, EPA proposes the identical HHC to address the Administrator's determination. Several specific proposals described in items 1 through 3, 5 through 7, 9 and 10 of Exhibit 1-1 may result in new or more stringent requirements for permittees or others. This analysis seeks to identify and estimate the potential incremental costs associated with new or more stringent requirements that result from the proposed WQS.
Other proposed WQS (items 4 and 8 in Exhibit 1-1) relate to state provisions that, as far as EPA is aware, have been rarely, if ever, invoked. Given that they would have been used only in very unusual circumstances, EPA's proposed WQS are therefore expected to have no material impacts and are not addressed further in this report.
Exhibit 1-1. EPA Disapprovals of Maine WQS and Proposed WQS
Disapproval
Current Maine WQS
(M.R.S.)
Proposed WQS[1]
1. Human Health Criteria (HHC) for waters in Indian lands
M.R.S. § 584, Appendix A
EPA calculated values assuming a fish consumption rate (FCR) of 286 grams per day incorporating new toxicity and exposure parameters for 96 pollutants.
2. Bacteria Criteria for waters in Indian lands
38 M.R.S §465 (1.B, 2B, 3.B and 4.B), §465-A(1.B), and §465-B(1.B, 2.B and 3.B). For Class B, C, GPA, SB, and SC waters, the criteria apply May 15 to September 30.
The bacteria content of Class AA and Class A waters shall be as naturally occurs, and in Class AA, Class A, Class B, Class C and Class GPA waters, Escherichia coli bacteria shall not exceed a geometric mean of 100 organisms per 100 milliliter (ml) obtained over a representative period of 30 days, nor shall 320 organisms per 100 ml be exceeded more than 10 percent of the time in any 30 day interval.
The bacteria content of Class SA waters shall be as naturally occurs, and in Class SA, Class SB, and Class SC waters, enterococcus bacteria shall not exceed a geometric mean of 30 organisms per 100 ml obtained over a representative period of 30 days, nor shall 110 organisms per 100 ml be exceeded more than 10 percent of the time in any 30 day interval.
In Class SA shellfish harvesting areas, the number of total coliform bacteria in samples representative of the waters in shellfish harvesting areas shall not exceed a geometric mean for each sampling station of 70 MPN (most probable number) per 100 ml, with not more than ten percent of samples exceeding 230 MPN per 100 ml for the taking of shellfish.
3. Ammonia aquatic life criteria for fresh water in Indian lands
DEP Rule Chapter 584, Appendix A
Tables 5a and 5b in U.S. EPA's Aquatic Life Ambient Water quality Criteria for Ammonia  -  Freshwater (EPA, 2013) provide the acute criteria values and Table 6 provides the chronic criteria.
4. Natural Conditions Clauses (only as they apply to human health) for waters in Indian lands
38 M.R.S §464(4.C) and 38 M.R.S. §420(2.A)
Proposed rule specifies that these provisions do not apply to HHC (no economic analysis)
5. pH for fresh waters in Indian lands
38 M.R.S §464(4.A(5))
Current EPA pH recommendation of 6.5 for lower end of range, and Maine's current 8.5 for upper end.
6. Temperature criteria for tidal waters in Indian lands
DEP Rule Chapter 582(5)
Maximum cumulative increase in weekly average temperature from all artificial sources is 1°C (1.8°F) year round, compared to baseline temperature, and provided that the summer weekly maximum of 18°C (64.4°F) is not exceeded; natural temperature cycles must be maintained.
7. Mixing zone policy for waters in Indian lands
38 M.R.S §451

Proposed rule clarifies the extent to which criteria may be exceeded in a mixing zone; specifies that mixing zone must be as small as necessary, and pollutant concentrations must be minimized and reflect the best practicable engineering design of the outfall to maximize initial mixing; requires use of methodologies in EPA's "Technical Support Document for Water Quality-based Toxics Control"; prohibits the use of a mixing zone for bioaccumulative pollutants and for bacteria; and establishes a number of restrictions to protect designated uses, including requirements that the mixing zone not result in lethality to organisms passing through or within the mixing zone, and not endanger critical areas such as breeding and spawning grounds, habitat for threatened or endangered species, and areas with sensitive biota, shellfish beds, fisheries, and recreational areas.
8. Waiver or modification of protection and improvement laws.
38 M.R.S §363-D
Proposed rule specifies that this statute does not allow waivers or modifications of WQS (no economic analysis).
9. Numeric criteria for dissolved oxygen (DO) in Class A waters throughout the State
38 M.R.S §465(2.B)
Includes Maine's year-round criteria of 7 ppm (7 mg/L) or 75 percent of saturation, whichever is higher, and adds more protective DO criteria  --  the 7-day mean DO concentration shall not be less than 9.5 ppm (9.5 mg/L), and the 1-day minimum DO concentration shall not be less than 8 ppm (8.0 mg/L)  --  for spawning areas in winter months.
10. Phenol criteria for protection of human health (water and organisms) to correct mathematical error, for state waters outside of Indian lands
DEP Rule Chapter 584 Appendix A
4,000 ug/l (based on EPA 304(a) 2015 HHC criteria and Maine's FCR of 32.4 g/day in state waters) (Promulgation for waters in Indian lands addressed in Item 1 above.)
1. Items in italics are expected to have no material effect on dischargers and are therefore not addressed in this economic analysis.

Purpose and Scope of the Analysis
The purpose of this analysis is to identify, using available water quality and discharge data and information, the incremental compliance actions and costs that publicly owned treatment works (POTWs) and industrial point source dischargers may incur as a result of EPA's proposed criteria, as well as costs that may be associated with actions to control pollution from nonpoint sources or to implement environmental programs.
Although the proposed rule does not establish any requirements directly applicable to regulated entities or other sources of pollution, state implementation may result in new or revised Maine Pollutant Discharge Elimination System (MEPDES) permit conditions for point source dischargers to incorporate revised water quality based effluent limitations (WQBELs). This analysis of impacts on point sources focuses specifically on the incremental costs that may be incurred by POTWs and industrial point source dischargers as a result of the proposed WQSs.
The proposed criteria may also result in incremental determinations that waters do not meet WQS, resulting in the waters being added to the list of impaired waters in the state. As such, the Maine Department of Environmental Protection (MEDEP) may need to develop additional total maximum daily loads (TMDLs) for impaired waters. There may also be incremental controls and costs associated with load allocations for nonpoint sources under such TMDLs to attain standards.
The scope of the analysis depends on the sets of waters relevant to the proposed WQS, either: (1) waters in Indian lands; (2) other state waters, as described below.
Proposed WQS Applicable only to Waters in Indian Lands
As discussed in the previous section, numerous disapprovals and corresponding proposed criteria and WQS are specific only to waters in Indian lands. EPA identified the relevant waters based on the extent of Indian lands (specifically, the reservation and trust lands) shown in Exhibit 1-2. The data layer used in creating the map in Exhibit 1-2 identifies Indian lands in New England.
Facilities that discharge into waters in Indian lands or their tributaries could contribute to exceedances of the proposed criteria in these waters and may incur costs as a result. As shown in Exhibit 1-2 and further described in Section 2.1.1, EPA determined that 33 facilities currently have permits to discharge to waters in Indian lands or their tributaries. In evaluating the implications of complying with proposed WQS applicable to these waters, EPA looked specifically for potential changes in permit conditions for these facilities. For example, EPA evaluated data for the 33 permitted dischargers to determine whether they have reasonable potential to cause or contribute to exceedances of the proposed WQS. When reasonable potential exists, EPA estimated revised effluent limits and potential control costs to meet the limits.
Exhibit 1-2: Indian lands in Maine and location of facilities with permits to discharge to waters in Indian lands or tributaries.

Proposed Criteria Applicable to All State Waters (DO) and to Waters Outside of Indian Lands (Phenol)
The proposed criteria for DO and phenol may have cost implications for point and nonpoint sources across the State.
EPA's proposed DO numeric criterion applies statewide to waters categorized as Class A. The proposed rule would retain Maine's year-round criteria, but add more protective DO criteria for spawning areas in winter months.
Approximately 19,500 miles of rivers and streams are categorized in Class A, representing 44 percent of all river and stream miles in the state (MEDEP, 2012). EPA identified 26 facilities that currently discharge to Class A waters and may incur costs associated with more stringent DO.
The proposed phenol criterion that would apply to waters outside of Indian lands may result in costs to facilities that have phenol in their effluent.
Organization of Report
The remainder of this report is organized as follows:
Section 2: Baseline for the Analysis  -  describes the current conditions for each pollutant addressed by the disapproval. For example, in the case of the HHC, the section describes applicable toxic criteria and MEDEP procedures for implementing the criteria in MEPDES permits, sources of toxic pollutants to surface waters, water quality impairments from toxic pollutants, and ongoing efforts to reduce and eliminate these impairments.
Section 3: Proposed Criteria  -  outlines the proposed WQS.
Section 4: Method for Estimating Potential Costs: Point Sources  -  describes the method for estimating compliance costs associated with baseline and proposed criteria for point sources in terms of revisions to MEPDES permits.
Section 5: Method for Identifying Potential Costs: Nonpoint Sources  -  describes the method for identifying potential for incremental impairment and compliance costs associated with baseline and proposed criteria for nonpoint sources.
Section 6: Potential Compliance Costs  -  provides estimates of potential costs to comply with the proposed WQS, and discusses the uncertainties associated with the estimates.
Section 7: References  -  provides the references used in the analysis.
Appendices provide data and information on individual facilities, and analyses of potential impacts under the proposed rule.
Exhibit 1-3 lists the proposed actions and indicates the sections of this report where the baseline conditions, proposed WQS, and estimated cost impacts are discussed.
Exhibit 1-3. Document Roadmap for Analysis of Effects and Costs of EPA Proposed Rules in Response to EPA Disapprovals[1]
Disapproval
Analysis Baseline
Effects of Proposed WQS
Incremental Cost Estimate
1. HHC for waters in Indian lands
Section 2.2.2
Section 3.1.1
Sections 4.1 and 6.1
2. Bacteria criteria for waters in Indian lands
Section 2.2.3
Section 3.1.2
Sections 4.2 and 6.1
3. Ammonia aquatic life criteria for fresh water in Indian lands
Section 2.2.4
Section 3.1.3
Section 4.3; no incremental costs
4. Natural Conditions Clauses (only as they applies to human health) for waters in Indian lands
No material effect (see Section 1.2.1)
No material effect (see Section 1.2.1)
N/A
5. pH for fresh waters in Indian lands
Section 2.2.5
Section 3.1.4

No incremental costs (see Section 3.1.4)
6. Temperature criteria for tidal waters in Indian lands
Section 2.2.6
Section 3.1.5
No incremental costs (see Section 3.1.5)
7. Mixing zone policy for waters in Indian lands
Section 2.2.7
Section 3.1.6
Sections 4.4 and 6.1
8. Waiver or modification of protection and improvement laws for all state waters.
No material effect (see Section 1.2.1)
No material effect (see Section 1.2.1)
N/A
9. Numeric criteria for DO in Class A waters statewide.
Section 2.2.8
Section 3.2
No incremental costs (see Section 3.2)
10. Phenol criteria for protection of human health (water and organisms) to correct mathematical error, for state waters outside of Indian lands
Section 2.2.2
Section 3.3
No incremental costs (see Section 3.3)
1. Items in italics are expected to have no material effect on dischargers and are therefore not addressed in this economic analysis.

Baseline for the Analysis
This section describes the applicable baseline for evaluating the incremental costs associated with the proposed WQS including potential sources of the pollutants of concern, current water quality impairments, disapproved water quality criteria and associated implementation procedures.
Sources of Pollutants to Surface Waters
Pollutants can be introduced to surface water through natural and human activities, including municipal and industrial effluents, stormwater discharges, septic systems, fish hatcheries, agricultural runoff, forestry, atmospheric deposition, and contaminated sediments.
Municipal and Industrial Dischargers
EPA's Integrated Compliance Information System (ICIS) lists 69 major and 409 non-major MEPDES permitted dischargers in Maine. Exhibit 2-1 provides the number of facilities by type (non-major/major) and category (based on standard industrial classification (SIC) codes provided in ICIS). It also shows the number of facilities that discharge to waters in Indian lands or their tributaries. Pollutants depend on the type of facility, but may include metals and other toxics, bacteria, nutrients, biological oxygen demand and other organic compounds, and elevated temperature from non-contact cooling water.
Most major dischargers in Maine are POTWs (57 out of 69 major dischargers). The remaining 12 major dischargers are industrial facilities categorized as wood product, pulp or paper mills (9 facilities), electrical services (2 facilities), or industrial machinery and equipment manufacturers (1 facility).
Of the 33 facilities that discharge to waters in Indian lands or their tributaries, 15 are POTWs (6 of which are major dischargers). The remaining dischargers consist of two wood products, pulp, or paper mills (one of which is a major discharger), nine hydropower projects, two educational establishments (listed under "Not Categorized or Unknown" in Exhibit 2-1), one food manufacturing facility, two drinking water treatment plants, and two fish hatcheries.
Exhibit 2-1. Number of Dischargers in Maine, by Category
Category (Based on SIC Code)
Non-Major
Major
All
Indian Lands or Tributaries
01-02: Crop and Animal Agriculture
                                      11
                                       0
                                      11

09: Aquaculture
                                      32
                                       0
                                      32
                                       2
16: Heavy Construction
                                       1
                                       0
                                       1

20: Food Manufacturing
                                      17
                                       0
                                      17
                                       1
22-23: Textile and Textile Products Manufacturing
                                       2
                                       0
                                       2

24-26: Wood Products, Pulp, and Paper
                                       5
                                       9
                                      14
                                       2
28: Chemicals and Chemical Preparations
                                       4
                                       0
                                       4

30-31: Plastics and Leather Products
                                       2
                                       0
                                       2

35-36: Industrial Machinery and Equipment
                                       1
                                       1
                                       2

37: Transportation Equipment Manufacturing
                                      13
                                       0
                                      13

40: Rail Transportation
                                       1
                                       0
                                       1

49: Utilities

   4911: Electric Services
                                      37
                                       2
                                      39
                                       9
   4952: Sewerage Systems
                                      97
                                      57
                                      154
                                      15
   All Other Utilities
                                      24
                                       0
                                      24
                                       2
50-51: Durable and Nondurable Goods
                                      14
                                       0
                                      14

65-97: All Others (Including Not Categorized)
                                      35
                                       0
                                      35

91-97: Government
                                       3
                                       0
                                       3

Not Categorized or Unknown
                                      110
                                       0
                                      110
                                       2
Total
                                      409
                                      69
                                      478
                                      33
Source: Summary developed based on data from the EPA ICIS database, and supplementary data from facility fact sheets. Categorizations based on 4-digit SIC codes. Includes permits with expiration date between 2/28/2012 and 8/30/2020.

Urban Stormwater
Stormwater discharges are generated by precipitation and runoff from land, pavements, building rooftops, and other surfaces. Stormwater from municipal and industrial areas may contribute pollutants, including sediment, nutrient, and toxic pollutants (such as the pollutants addressed by the proposed HHC), to surface waters (for example, see MEDEP, 2014). Changes in the routing, magnitude, and timing of the stormwater also results in changes in the flow regime of rivers, including flash floods and associated bank erosion and habitat destruction.
Maine has a population of 1.3 million people, concentrated mostly in the southern part of the state and the coastline. While only approximately 3 percent of Maine's landscape is developed lands and paved ways (MEDEP, 2014), stormwater runoff and other development-related impacts are significant causes of impairment or stressors for the state's waters (see Section 2.2).
In particular, runoff from impervious cover is responsible for 54 miles of rivers and streams not meeting WQS for aquatic life use, while other stormwater-related sources are responsible for impairment of 92 miles of rivers and streams (MEDEP, 2012). Stormwater runoff is also a significant source of lake impairments. To address stormwater runoff as the source of impairment in 29 segments of rivers and streams across the state, MEDEP developed a statewide impervious cover TMDL. The TMDL sets targets for the percentage of total impervious cover (%IC) in watersheds and determines reductions in stormwater runoff volume and associated pollutants that may be needed to meet WQS. These reductions may be achieved by using best management practices (BMPs) and low impact development (LID) techniques, as described in a watershed management plan (WMP) specific to each location. The use of the %IC metric is based upon the observed relationship between the amount of human disturbance within a watershed and the decline in aquatic communities in streams and overall ecosystem health.
MEDEP regulates land use activities through five statutes: the Erosion and Sedimentation Control Law; the Site Location of Development Law; the Storm Water Management Law; the Mandatory Shoreland Zoning Act; and the Natural Resources Protection Act. These regulations control the type of development activities that may take place in various areas and BMPs that must be implemented to mitigate impact during and after construction. Other programs focus on reducing impacts from fertilizer application and road-salt management.
MEDEP regulates stormwater discharges from small municipal separate storm sewer systems (MS4s) through a general permit (MEDEP, 2013). This permit covers 30 municipalities, eight state or federally owned facilities, and 2 transportation agencies (Maine Department of Transportation and Maine Turnpike Authority). This general permit requires the permittees to develop, implement, and enforce a stormwater management program (SWMP) including six minimum control measures: public education and outreach on stormwater impacts, public involvement and participation, illicit discharge detection and elimination, construction site stormwater runoff control, post-construction stormwater management in new development and redevelopment, and pollution prevention (P2)/good housekeeping for municipal operations.
Industrial dischargers, including those engaged in manufacturing, transportation, mining, and steam electric power industries, scrap yards, landfills, certain sewage treatment plants, and hazardous waste management facilities may have stormwater requirements in their individual MEPDES permits. Additionally, MEDEP issued a Multi-Sector Industrial Stormwater general permit (MEDEP, 2011), which covers stormwater discharges from industrial activities and requires facility owners to file a notice of intent (NOI) for coverage and develop a Stormwater Pollution Prevention Plan that includes BMPs to prevent, control, and treat stormwater pollution, a monitoring plan and discussion of the site controls that the discharger will implement to prevent stormwater pollution. The permit also includes additional requirements for 31 specific sectors.
Onsite Wastewater Disposal Systems
According to the Maine Division of Environmental Health (MEDEH, 2015a), Maine households are predominantly rural, relying heavily on onsite wastewater disposal systems (OSDS), or septic systems. Data from the U.S. Census Bureau (1990) indicates that in 1990, over half of homes in Maine utilized these systems (301,373 compared with 266,344 on public sewerage systems and 19,328 using some other means). The number of households in Maine has increased since 1990 by about 24 percent (based on 727,632 households in 2014 U.S. Census Bureau, 2014). More recent data on the share of households using OSDS is not available; however, the MEDEH processes approximately 10,000 system permits annually (MEDEH, 2015b), suggesting that OSDS are still a predominant wastewater disposal method for Maine households.
When properly installed, maintained, and operated, these systems can provide safe and effective sanitation in areas that lack centralized municipal wastewater collection. Malfunctioning disposal systems can cause bacterial contamination and deliver excess nutrients to surface waters. Maine's Department of Health and Human Services (DHHS) is responsible for rules addressing the disposal of wastewater, sets design and installation criteria, issues permits and installer certifications, conducts inspections, and provides grants to facilitate replacement of malfunctioning septic systems.
Agriculture and Forestry
Forests account for over two thirds (69 percent) of Maine's landscape while land in agricultural production represents another 6 percent (MEDEP, 2014). Pesticides applied to agricultural or forestry lands can reach surface waters through irrigation return flow, stormwater runoff, and erosion of soils. Timber harvesting operations can also release sediment and nutrients. The Department of Agriculture, Conservation, and Forestry (DACF) and the Maine Forest Services, respectively, have primary responsibility to control runoff from agricultural and forestry lands.
MEDEP has identified agriculture as a source of impaired water quality for 6 lakes (10,532 acres) and 358 miles of rivers and streams. Pollutants of concern in these waters include bacteria, soil, fertilizers, and pesticides (MEDEP, 2014). The DACF promotes the widespread use of agricultural BMPs through the Nutrient Management Act, which primarily aims to reduce nutrient runoff from livestock, and the Agricultural Compliance Program, which promotes, inspects, and assists with the implementation of agricultural BMPs.
Maine has the highest percentage of forested land of any state, and approximately 450,000 acres are harvested annually (MEDEP, 2014). The Maine Forestry Service promotes the widespread use of forestry BMPs for all forestry operations. Pursuant to the Nonpoint Source (NPS) Management Program Statute (38 M.R.S. Article 1-F), it has developed BMP guidance and programs, and provides BMP assistance to landowners and wood harvesters.
Note that fish hatcheries are point sources covered by individual MEPDES permits in Maine and are therefore addressed in this analysis.
Atmospheric Deposition
Atmospheric deposition may be a potential nonpoint source to surface waters through either direct or indirect deposition. Direct deposition occurs when pollutants are deposited directly on surface waters from the atmosphere. Indirect deposition reflects the process by which metals and other pollutants such as pesticides deposited on the land surface are washed off during storm events and enter surface water through stormwater runoff.
Maine has a statewide fish consumption advisory due to mercury levels. In 2007, an estimated 98 percent of the total load of mercury to Northeast freshwater bodies was due to atmospheric deposition (Connecticut DEP et al., 2007). Since then, EPA has promulgated regulations aimed at curbing emissions of mercury from coal-fired power plants and other sources. Atmospheric deposition is not directly addressed through any existing regulation, but may be indirectly addressed through TMDLs in estimating load allocations. Maine is covered by the Northeast Regional Mercury TMDL, which outlines strategies for reducing mercury concentrations in fish and achieving a target of 0.2 milligrams per kilogram (mg/kg) or parts per million (ppm) fish tissue residue of mercury in the edible portion of fish in Maine. These strategies include focusing on atmospheric deposition to achieve the bulk of loading reductions while ensuring that loadings from point sources remain small.
Contaminated Sediments
When pollutants enter a waterbody through runoff, precipitation, or other means, they can accumulate in sediments and contribute to poor water quality for many years (U.S. EPA, 2012). Many waterbody sediments are contaminated by legacy pollutants including polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and other pesticides, which contribute to impairments of these waters even decades after discharges of these pollutants have ceased. Thus, several of Maine's major freshwater streams (e.g., Androscoggin River, Kennebec River, and Penobscot River) have fish consumption advisories based on elevated DDT, dioxin, and PCB levels. A state-wide advisory for dioxins and PCBs also applies to all coastal waters (U.S. EPA, 2015b). These advisories either provide recommended guidelines for the consumption of fish by certain subpopulation(s) or advise against consumption of fish from the affected waterbodies by the general population. In general, the state advises consumers to follow the most limiting guideline, based on mercury, DDT, dioxins, or PCBs.
Baseline Water Quality and Criteria
Water Quality Impairments
According to Maine's 2012 Integrated Report, which identifies impaired waters and reports on the status of water quality statewide, 95 percent of assessed rivers and streams miles, 91 percent of assessed lake acres and 94 percent of assessed marine waters fully attained the State's WQS (MEDEP, 2012). For the remaining waters, MEDEP identified one or more sources of impairment because of exceedances of one or more applicable WQS. Exhibit 2-2 summarizes causes of impairments for rivers and streams, lakes, and marine waters.
Exhibit 2-2. Cumulative Size of Impaired Waters by Listing Cause/Stressor Type
Cause of Impairment
River/stream (miles)
Lake
(acres)
Marine waters (square miles)
Pathogens / Bacteria
                                                                            175

                                                                            159
   Nonpoint sources and combined sewer overflows
                                                                       Variable

                                                                       Variable
Aquatic Life Criteria

   Integrated effects including biocriteria, habitat and
   nutrient biological indicators
                                                                            408

   Habitat assessment (lake)

                                                                         48,964

   Marine life

                                                                              1
Oxygen depletion
                                                                            475
                                                                            634

   Dissolved oxygen
                                                                            464

                                                                              6
   BOD
                                                                             21

   Sediment oxygen demand

                                                                          <1
Altered flow regime
                                                                             31

   Fish passage barrier
                                                                            4.5

Nutrients
                                                                            243

   Nutrient/eutrophication, biological indicators
                                                                            184

                                                                              2
   Phosphorus (total)

                                                                         36,234

Total inorganics
                                                                             26

   Methylmercury

                                                                        986,952

   Metals-copper

                                                                          <1
Total organics
                                                                            422

   Dioxins
                                                                            371

                                                                          2,846
   PCBs
                                                                            418

                                                                          2,846
   Pesticides
                                                                            217

   DDT
                                                                            214

pH, acidity, caustic conditions
                                                                              1

Sedimentation
                                                                             15

Harmful algae blooms
                                                                              8

Secchi Disk Transparency

                                                                         35,600

Turbidity

                                                                          7,865

Unknown

                                                                              2
Source: Based on 2012 Maine Integrated Water Quality Report; Tables 4-10 to 4-14).

The most recent assessment identified industrial and municipal (primarily POTW) point source discharges as the first and fifth most important sources of impairments, respectively, for rivers and streams in terms of impaired miles. These sources represent 452.5 miles of impaired rivers and 168 miles of impaired streams. Other impairment sources include unspecified non-point sources, agriculture, development-related sources (such as urban stormwater, impervious surfaces/parking lot runoff, and post-development erosion and sedimentation), dam or impoundment, and others.
Sources of impairments for lakes include atmospheric deposition of toxics (which represents the largest impact in terms of impaired lake area), followed by impacts from hydro-structures, flow regulation/modification, residential development, agriculture (e.g., crop production and livestock grazing or feeding operations), and others.
Finally, MEDEP identified legacy pollutants as the most important contributor to impairments in marine waters, by impaired area, with CSOs being a variable contributor.
Since 1998, the state developed, and EPA approved, TMDLs for 23 lakes and 14 rivers/streams to address impairments previously identified by the state.
Toxics
Exhibit 2-3 shows the Maine HHC (06-096 Chapter 584, Appendix A) that EPA disapproved and for which EPA proposes to promulgate HHC. These are the "baseline" criteria against which EPA's proposed criteria are compared for evaluating potential incremental cost impacts. The table also shows aquatic life criteria for freshwater and marine waters, where they exist for the pollutants for which there are HHC.
Exhibit 2-3. Baseline Water Quality Criteria for Toxic Priority Pollutants in Maine[1]
Pollutant
Freshwater Aquatic Life (ug/L)
Marine Aquatic Life (ug/L)
Human Health (ug/L)

Acute
Chronic
Acute
Chronic
Water and Organisms
Organisms Only
1,1,2,2-Tetrachloroethane

0.16
2.2
1,1,2-Trichloroethane

0.58
8.42
1,1-Dichloroethylene

320
3900
1,2,4,5-Tetrachlorobenzene

0.55
0.58
1,2,4-Trichlorobenzene

25
38
1,2-Dichlorobenzene

330
700
1,2-Dichloropropane

0.50
7.9
1,2-Diphenylhydrazine

0.03
0.11
1,2-Trans-Dichloroethylene

140
5500
1,3-Dichlorobenzene

250
520
1,3-Dichloropropene

0.34
11.4
1,4-Dichlorobenzene

50
105
2,4,5-Trichlorophenol

1300
2000
2,4,6-Trichlorophenol

0.93
1.31
2,4-Dichlorophenol

63.3
160
2,4-Dimethylphenol

280
460
2,4-Dinitrophenol

68.4
2900
2,4-Dinitrotoluene

0.11
1.83
2-Chloronaphthalene

650
850
2-Chlorophenol

55.2
80.6
2-Methyl-4,6-Dinitrophenol

12.5
155
3,3'-Dichlorobenzidine

0.013
0.015
4,4'-DDD

0.00017
0.00017
4,4'-DDE

0.00012
0.00012
4,4'-DDT
1.1
0.001
0.13
0.001
0.00012
0.00012
Acenaphthene

430
540
Acrolein
3
3

3.9
5.0
Aldrin
3

1.3

2.7E-05
2.7E-05
alpha-BHC

0.0017
0.0026
alpha-Endosulfan
0.22
0.056
0.034
0.0087
39
48
Anthracene

7100
22000
Antimony

5.5
350
Benzene-Upper CSF

0.58
7.55
Benzo (a) Anthracene

0.003
0.01
Benzo (a) Pyrene

0.003
0.01
Benzo (b) Fluoranthene

0.003
0.01
Benzo (k) Fluoranthene

0.003
0.01
beta-BHC

0.006
0.009
beta-Endosulfan
0.22
0.056
0.034
0.0087
39
48
Bis(2-Chloro-1-Methylethyl) Ether

1350
35000
Bis(2-Chloroethyl) Ether

0.029
0.28
Bis(2-Ethylhexyl) Phthalate

0.8
1.19
Bromoform

4.2
73
Butylbenzyl Phthalate

900
1050
Carbon Tetrachloride

0.23
0.89
Chlordane
2.4
0.0043
0.09
0.004
0.00044
0.00044
Chlorobenzene

120
840
Chlorodibromomethane

0.40
6.94
Chrysene

0.003
0.01
Cyanide
22
5.2
1
1
140
140
Dibenzo (a,h) Anthracene

0.003
0.01
Dichlorobromomethane

0.53
9.3
Dieldrin
0.24
0.056 O
0.71
0.0019
2.9E-05
2.9
Diethyl Phthalate

13000
24000
Dimethyl Phthalate

221000
600000
Di-n-Butyl Phthalate

1400
2400
Dinitrophenols

68
2860
Endosulfan Sulfate

39
48
Endrin
0.086
0.036
0.037
0.0023
0.032
0.032
Endrin Aldehyde

0.16
0.16
Ethylbenzene

435
1150
Fluoranthene

71
75
Fluorene

950
2100
gamma-BHC (Lindane)
0.95

0.16

0.68
0.1
Heptachlor
0.52
0.0038
0.053
0.0036
4.3E-05
4.3E-05
Heptachlor Epoxide
0.52
0.0038
0.053
0.0036
2.1E-05
2.1E-05
Hexachlorobenzene

0.0002
0.0002
Hexachlorobutadiene

0.43
9.96
Hexachlorocyclohexane-Technical

0.0123
0.0414
Hexachlorocyclopentadiene

39
600
Hexachloroethane

1.04
1.78
Indeno (1,2,3-cd) Pyrene

0.003
0.01
Isophorone

35
520
Methoxychlor

0.03

0.03
100

Methylene Chloride

4.6
320
Methylmercury

0.2 mg/Kg
Nickel
120.2
13.4
75
8.28
400
1000
Nitrobenzene

16.7
370
Nitrosamines

0.0008
1.24
N-Nitrosodibutylamine

0.0061
0.118
N-Nitrosodiethylamine

0.0008
1.24
N-Nitrosodimethylamine

0.00069
1.63
N-Nitrosodi-n-propylamine

0.005
0.27
N-Nitrosodiphenylamine

2.23
3.24
N-Nitrosopyrrolidine

0.016
18.4
Pentachlorobenzene

0.79
0.81
Pentachlorophenol
8.72
6.69
13
7.9
0.25
1.64
Phenol

10514
462963
Polychlorinated Biphenyls (PCBs)

0.014

0.03
3.5E-05
3.5E-05
Pyrene

710
2160
Selenium

5
291
71
162
2250
Toluene

1200
8100
Toxaphene
0.73
0.0002
0.21
0.0002
0.00015
0.000155
Trichloroethylene

2.37
16.2
Vinyl Chloride

0.025
1.32
Zinc
30.6
30.6
95
86
6000
14000
Source: MEDEP Regulation 06-096 CMR 584, Appendix A,and 38 MRS § 420(1-B). See original source for additional notes on criteria applicability or basis.
[1] The table does not include additional priority pollutants for which the State of Maine established aquatic life criteria only (e.g., Cadmium, Chromium III and Chromium VI).

As discussed in Section 2.1.5, a large fraction of state waters are impaired for mercury from atmospheric deposition from sources outside the region. State law prohibits the discharge of mercury and directs facilities to develop and implement P2 practices to reduce and remove mercury discharges over time (38 MRS § 420), and authorizes MEDEP to establish interim discharge limits to reduce the discharge of mercury and achieve ambient water quality criteria for mercury (38 MRS § 413(11)). MEDEP Rule, in turn (06-096 Chapter 519) specifies that such interim mercury limits must be based upon  -  and no less stringent statistically  -  than past discharge levels, and that such interim limits shall not authorize any discharge of mercury that would cause or contribute to receiving water concentrations of mercury that exceed any water quality criteria published by EPA. Under Chapter 519, MEDEP controls mercury discharges from point source dischargers to surface waters through effluent limitations, monitoring requirements, and P2 plan requirements. These limitations and requirements apply to all permittees that have the potential to discharge wastewaters that may contain or come into contact with mercury. Each facility is required to develop and implement a P2 plan (based on model plans developed by MEDEP), and conduct effluent monitoring for mercury at least 3 times a year. Additionally, MEDEP establishes interim mercury effluent limits for each permittee based on the facility's mean mercury effluent concentration adjusted to account for the standard error and confidence level. Further, in accordance with Chapter 519, the facility does not violate the ambient criteria for mercury if the facility is in compliance with its interim discharge limit or with a remediation or corrective action plan, license or order approved either by MEDEP or the U.S. EPA.
As discussed later in Section 3, EPA is proposing HHC (based on the consumption of water and organisms and for consumption of organisms only) for waters in Indian lands to address the disapproved criteria presented in Exhibit 2-3.
There are little available data on ambient levels of these pollutants in waters in Indian lands. EPA reviewed the available monitoring data to characterize the quality of surface waters in Indian lands. EPA identified 66 monitoring locations that were sampled during the period of 2000 through 2015 within Indian lands, with very little monitoring data for the set of toxic pollutants for which EPA is proposing HHC.
As discussed in Section 1.2.2, EPA is proposing two phenol criteria for water plus organisms  --  one for waters in Indian Lands and one for all other state waters. EPA found no data to characterize baseline phenol levels in either waters in Indian lands or other state waters; available water quality monitoring data provide no water column results for phenol and the integrated assessment report makes no mention of phenol as a concern.
Bacteria
As summarized in Exhibit 2-2, as of the 2012 integrated water quality assessment, approximately 175 miles of rivers and streams and 159 square miles of estuarine and marine waters (excluding waters listed based on Combined Sewer Overflows) were identified as impaired due to elevated bacterial counts. Bacteria levels are monitored by MEDEP in selected urban streams, by the Maine Healthy Beaches program in swimming beaches and in tidal waters that influence bacterial loads to recreational areas, and by the Department of Marine Resources (DMR) to determine shellfish harvest closures (MEDEP, 2012).
In 2009, the State completed the development of a statewide bacteria TMDL to address sources of bacteria in both freshwaters and marine waters associated with impairments of certain river and stream segments and estuarine and marine segments in several major basins. The TMDL aims to meet the bacterial WQS for recreation and shellfish consumption at the point of discharge for all sources and to implement BMPs to reduce bacteria loadings from non-point sources (ENSR, 2009).
Through this action, EPA is proposing recreational bacteria criteria for waters in Indian lands. Accordingly, EPA reviewed water quality reported for these waters more specifically to assess baseline conditions. Based on information provided on the Maine Healthy Beaches program website, none of the coastal beaches monitored by that program are located in or near Indian lands. Monitoring data submitted to the EPA's Water Quality Portal from other programs for these waters is limited to 62 observations from 20 locations sampled in 2005, 2008 or 2011. The data show maximum reported E. coli levels of 64 cfu/100 ml (60 samples) and maximum enterococci levels of 71 cfu/100 ml (2 samples). EPA notes that three plants discharge to waters in Indian lands or their tributaries (St. Croix River and Piscataquis River) that MEDEP previously listed as impaired due to elevated bacterial levels, as detailed in the statewide bacteria TMDL.
EPA is also proposing total coliform bacteria criteria for shellfishing in Class SA waters in Indian lands. At present it appears that there are no Class SA waters in Indian lands.
Ammonia
Maine's ammonia criteria for freshwater depend on pH and temperature (T). Chapter 584 specifies that the one-hour average concentration of total ammonia nitrogen (in mg N/L) shall not exceed, more than once every three years on the average, the CMC (criterion maximum concentration, or acute criterion) calculated using the following equations:
CMC=0.2751+107.204-pH+39.01+10pH-7.204
Whereas the thirty-day average concentration of total ammonia nitrogen (in mg N/L) shall not exceed, more than once every three years on the average, the CCC (criterion continuous concentration, or chronic criterion) calculated using the following equation:
  CCC=0.05771+107.688-pH+2.4871+10pH-7.688xmin(2.85,1.45x100.028(25-T))
In addition, the highest four-day average within the 30-day period shall not exceed 2.5 times the CCC.
At a temperature of 25ºC and pH of 7.0, the acute criterion is 24.1 mg/L whereas the chronic criterion is 3 mg/L. Through this action, EPA is proposing ammonia criteria for waters in Indian lands. Accordingly, EPA reviewed ammonia concentrations for these waters to assess baseline conditions. None of the waters are listed as impaired due to ammonia levels. Available water quality monitoring data shows only six water samples collected from waters in Indian lands were analyzed for ammonia levels. These samples were all collected by the USGS in 2008 or 2009 and show levels that range between 0.01 mg/L and 0.036 mg/L as N.
pH
Maine law, at 38 M.R.S §464(4.A(5)), prohibits effluent discharges that cause the pH of fresh waters to fall outside of the 6.0 to 8.5 range. A review of existing permits for facilities that discharge to waters in Indian lands also show additional provisions allowing discharges outside the specified pH range for effluent if the discharge is within 0.5 standard units (SU) of the pH of the ambient receiving water pH (e.g., Woodland Pulp permit).
In addition to industrial point source discharges, pH levels may be affected by atmospheric deposition and impacts from legacy pollution. There are no rivers or streams in Indian lands that are listed as impaired for pH.
EPA reviewed available water quality monitoring data collected from waters in Indian lands. The data show pH values ranging from 3.6 to 9.1.
Tidal Temperature
MEDEP Chapter 582 establishes a not-to-exceed criterion of 85ºF outside of the discharge mixing zone in marine waters. Maine also limits discharges from causing the monthly mean of the daily maximum ambient temperatures in any tidal waterbody to be raised more than 4ºF at any time, or more than 1.5ºF from June 1 to September 1 (summer months). Through this action, EPA is proposing tidal temperature criteria for tidal waters in Indian lands, which consist of the waters within the intertidal zone at the Passamaquoddy Pleasant Point reservation. Currently there are no permittees that discharge heat to tidal waters in Indian lands.
Mixing Zone
The mixing zone policy for Maine is contained in 38 MRS Section 451 "Enforcement Generally" which states:
The purpose of a mixing zone is to allow a reasonable opportunity for dilution, diffusion or mixture of pollutants with the receiving waters before the receiving waters below or surrounding a discharge will be tested for classification violations. In determining the extent of any mixing zone to be established under this section, the department may require from the applicant testimony concerning the nature and rate of the discharge; the nature and rate of existing discharges to the waterway; the size of the waterway and the rate of flow therein; any relevant seasonal, climatic, tidal and natural variations in such size, flow, nature and rate; the uses of the waterways in the vicinity of the discharge, and such other and further evidence as in the department's judgment will enable it to establish a reasonable mixing zone for such discharge. An order establishing a mixing zone may provide that the extent thereof varies in order to take into account seasonal, climatic, tidal and natural variations in the size and flow of, and the nature and rate of, discharges to the waterway.
Maine's mixing zone policy does not specify how such zones are to be established (other than through the application of best professional judgment).
Within the set of 33 facilities that discharge to waters in Indian lands or their tributaries, EPA identified Woodland Pulp LLC as the only facility for which the permit establishes a mixing zone that may extend to waters in Indian lands.
Woodland Pulp LLC is currently permitted to contribute large thermal loadings to the St. Croix River and has an extensive thermal mixing zone (9.3 miles long). MEDEP established the limits of this mixing zone many years (and permit cycles) ago and information on site-specific studies or models used to establish compliance is limited or not readily available for review. The current permit employs a variation of a mass balance using effluent temperature and river flow to calculate predicted river temperature increase at the edge of the mixing zone and compare this temperature to applicable criteria. There are currently no in-stream monitoring requirements in the permit, although it does require the permittee to investigate technological alternatives to reduce cumulative thermal loading from the facility and report on projects and estimate reduced heat load as part of the next permit application.
Dissolved Oxygen
Maine's standards for Class A waters set minimum DO concentrations at 7 ppm and minimum DO saturation at 75 percent. EPA reviewed water quality monitoring data for sampling locations on Class A waters. Of 193 samples collected by MEDEP over the last five years, eight showed DO levels that were less than MEDEP's criteria of 7 ppm or 75 percent saturation.
As of its 2012 Integrated Report, MEDEP added one Class A stream in the list of rivers and streams impaired due to DO levels: a 15.78 miles segment of Prestile Stream above a dam in Mars Hill. A TMDL has been approved for this waterbody to address water quality stressors associated with nonpoint source runoff.
Impact from nonpoint sources is an important factor in river and stream DO impairments more generally. Thus, according to MEDEP's water quality assessment for 2012, two thirds of the 42 waters listed as impaired due to oxygen depletion (across water quality classes) had agriculture or other nonpoint sources as a probable source for the impairment.

Proposed Criteria
This section describes the criteria EPA is proposing for waters in Indian lands (Section 3.1) and for other state waters (Section 3.2). The discussion highlights those proposed criteria that may have cost implications, as further analyzed in Sections 4 and 5.
Proposed Criteria for Waters in Indian Lands
Human Health Criteria
Exhibit 3-1 summarizes the proposed HHC for waters in Indian lands derived using the fish consumption rate of 286 g/day and EPA's most recent recommendations for other criteria inputs. For comparison, the table also provides MEDEP's baseline criteria, which were derived using a FCR of 32.4 g/day. Finally, Exhibit 3-1 provides MEDEP's specified reporting limits (RLs), which represent the minimum level to which dischargers need to measure each pollutant according to the existing permit conditions.
Of particular relevance for this analysis are proposed criteria that result in more stringent criteria than exist in the baseline. EPA did not consider further those pollutants for which the proposed HHC are higher than existing aquatic life criteria because the aquatic life criteria would be the determining factor in setting effluent limitations. The proposed HHC for alpha-endosulfan, beta-endosulfan, nickel, selenium, and zinc (2 ug/L, 3 ug/L, 20 ug/L, 21 ug/L, and 300 ug/L, respectively) are less stringent than the state's existing freshwater aquatic life criteria, which EPA has approved for waters in Indian lands (0.056 ug/L, 0.056 ug/L, 13.4 ug/L, 5.0 ug/L, and 30.6 ug/L, respectively; see Exhibit 2-3). Therefore EPA assumed that the proposed rule would not lead to additional compliance costs for these pollutants, and EPA did not evaluate them further.
Exhibit 3-1. Proposed Human Health Criteria for the Consumption of Water and Organisms and Organisms Only (ug/L)
Pollutant[1]
Proposed Human Health Criterion
Maine DEP Reg. 584 Appendix A Table 1
Maine DEP Reporting Limit

Water and Organisms[2]
Organisms Only[3]
Water and Organisms
Organisms Only

1,1,2,2-Tetrachloroethane
0.09
0.2
0.16
2.2
7
1,1,2-Trichloroethane
0.31
0.66
0.58
8.42
5
1,1-Dichloroethylene
300
1000
320
3900
3
1,2,4,5-Tetrachlorobenzene
0.002
0.002
0.55
0.58
not found
1,2,4-Trichlorobenzene
0.0056
0.0056
25
38
5
1,2-Dichlorobenzene
200
300
330
700
5
1,2-Dichloropropane
-
2.3
0.50
7.9
6
1,2-Diphenylhydrazine
0.01
0.02
0.03
0.11
20
1,3-Dichlorobenzene
1
1
250
520
5
1,3-Dichloropropene
0.21
0.87
0.34
11.4
5
1,4-Dichlorobenzene
-
70
50
105
5
2,4,5-Trichlorophenol
40
40
1300
2000
2.5
2,4,6-Trichlorophenol
 0.20
0.21
0.93
1.31
5
2,4-Dichlorophenol
4
4
63.3
160
5
2,4-Dimethylphenol
80
200
280
460
5
2,4-Dinitrophenol
9
30
68.4
2900
45
2,4-Dinitrotoluene
0.036
0.13
0.11
1.83
6
2-Chloronaphthalene
90
90
650
850
5
2-Chlorophenol
20
60
55.2
80.6
5
2-Methyl-4,6-Dinitrophenol
1
2
12.5
155
not found
3,3'-Dichlorobenzidine
0.0096
0.011
0.013
0.015
16.5
4,4'-DDD
9.3E-06
9.3E-06
0.00017
0.00017
0.05
4,4'-DDE
1.3E-06
1.3E-06
0.00012
0.00012
0.05
4,4'-DDT
2.2E-6
2.2E-06
0.00012
0.00012
0.05
Acenaphthene
6
7
430
540
5
Acrolein
3
-
3.9
5.0
NA
Aldrin
5.8E-08
5.8E-08
2.7E-05
2.7E-05
0.15
alpha-BHC
2.9E-05
2.9E-05
0.0017
0.0026
0.2
alpha-Endosulfan
2
2
39
48
0.05
Anthracene
30
30
7100
22000
5
Antimony
 4.8
 45
5.5
350
5
Benzene
0.40
1.2
0.58
7.55
5
Benzo (a) Anthracene
9.8E-05
9.8E-05
0.003
0.01
8
Benzo (a) Pyrene
9.8E-06
9.8E-06
0.003
0.01
5
Benzo (b) Fluoranthene
9.8E-05
9.8E-05
0.003
0.01
5
Benzo (k) Fluoranthene
0.00098
0.00098
0.003
0.01
5
beta-BHC
0.0010
0.0011
0.006
0.009
0.05
beta-Endosulfan
3
3
39
48
0.05
Bis(2-Chloro-1-Methylethyl) Ether
100
300
1350
35000
6
Bis(2-Chloroethyl) Ether
0.026
0.16
0.029
0.28
6
Bis(2-Ethylhexyl) Phthalate
0.028
0.028
0.8
1.19
10
Bromoform
4.0
8.7
4.2
73
5
Butylbenzyl Phthalate
0.0077
0.0077
900
1050
5
Carbon Tetrachloride
0.2
0.3
0.23
0.89
5
Chlordane
2.4E-05
2.4E-05
0.00044
0.00044
0.1
Chlorobenzene
40
60
120
840
6
Chlorodibromomethane
-
1.5
0.40
6.94
3
Chrysene
-
0.0098
0.003
0.01
5
Cyanide
4
30
140
140
5
Dibenzo (a,h) Anthracene
9.8E-06
9.8E-06
0.003
0.01
5
Dichlorobromomethane
-
2
0.53
9.3
3
Dieldrin
9.3E-08
9.3E-08
2.9E-05
2.9E-05
0.05
Diethyl Phthalate
50
50
13000
24000
5
Dimethyl Phthalate
100
100
221000
600000
5
Di-n-Butyl Phthalate
2
2
1400
2400
5
Dinitrophenols
10
70
68
2860
not found
Endosulfan Sulfate
3
3
39
48
0.1
Endrin
0.002
0.002
0.032
0.032
0.05
Endrin Aldehyde
0.09
0.09
0.16
0.16
0.05
Ethylbenzene
8.9
 9.5
435
1150
10
Fluoranthene
1
1
71
75
5
Fluorene
5
5
950
2100
5
gamma-BHC (Lindane)
0.33
-
0.68
0.1
0.15
Heptachlor
4.4E-07
4.4E-07
4.3E-05
4.3E-05
0.15
Heptachlor Epoxide
2.4E-06
2.4E-06
2.1E-05
2.1E-05
0.1
Hexachlorobenzene
5.9E-06
5.9E-06
0.0002
0.0002
5
Hexachlorobutadiene
0.0007
0.0007
0.43
9.96
5
Hexachlorocyclohexane-Technical
0.00073
0.00076
0.0123
0.0414
not found
Hexachlorocyclopentadiene
0.3
0.3
39
600
10
Hexachloroethane
0.01
0.01
1.04
1.78
5
Indeno (1,2,3-cd) Pyrene
9.8E-05
9.8E-05
0.003
0.01
5
Isophorone
28
140
35
520
5
Methoxychlor
0.001
-
100
-
not found
Methylene Chloride
-
90
4.6
320
5
Methylmercury[4]

0.02 mg/kg in fish tissue

0.2 mg/kg mercury in fish tissue

Nickel
20
24
400
1000
5
Nitrobenzene
10
40
16.7
370
5
Nitrosamines
 0.0007
 0.0322
0.0008
1.24
not found
N-Nitrosodibutylamine
 0.0044
 0.015
0.0061
0.118
not found
N-Nitrosodiethylamine
 0.0007
 0.0322
0.0008
1.24
not found
N-Nitrosodimethylamine
0.00065
0.21
0.00069
1.63
5
N-Nitrosodi-n-propylamine
 0.0042
 0.035
0.005
0.27
10
N-Nitrosodiphenylamine

 0.40
0.42
2.23
3.24
5
N-Nitrosopyrrolidine
-
2.4
0.016
18.4

Pentachlorobenzene
0.008
0.008
0.79
0.81
not found
Pentachlorophenol
0.003
0.003
0.25
1.64
20
Phenol
3000
20000
10514
462963
5
Polychlorinated Biphenyls (PCBs)
4.5E-06

4.5E-06
3.5E-05
3.5E-05
0.3
Pyrene
2
2
710
2160
5
Selenium
21
58
162
2250
5
Toluene
24
39
1200
8100
5
Toxaphene
5.3E-05
5.3E-05
0.00015
0.000155
1
Trans-1,2-Dichloroethylene
90
300
140
5500
5
Trichloroethylene
0.3
0.5
2.37
16.2
3
Vinyl Chloride
0.019
0.12
0.025
1.32
5
Zinc
300
360
6000
14000
5
FCR = fish consumption rate
1. EPA disapproved HHCs for arsenic, thallium and 2,3,7,8-TCDD (Dioxin) but is not proposing criteria for these pollutants at this time.
2. Based on a total FCR of 286 g/day where the consumption rate ascribed to each trophic level was based on the same relative percent and trophic specific bioaccumulation factors adopted by EPA (2015a) when available and including a body weight of 80 kg and drinking water intake of 2.4 L/day and other 2015 updated parameters as available; For compounds not updated in 2015, proposed criteria are based on a FCR of 286 g/day and a relative source contribution of 0.2 save for antimony (RSC of 0.4), body weight of 80 kg, drinking water intake rate of 2.4 L/day, and bioconcentration factors and toxicity values from U.S. EPA (2002).
3. Based on total FCR of 286 g/day where the consumption rate ascribed to each trophic level was based on the same relative percent and trophic specific bioaccumulation factors adopted by EPA (2015a) when available including a body weight of 80 kg and other 2015 updated parameters as available; For compounds not updated in 2015, proposed criteria are based on a FCR of 286 g/day and a relative source contribution of 0.2 save for antimony (RSC of 0.4), body weight of 80 kg, and bioconcentration factors and toxicity values from U.S. EPA (2002).
4. This is a fish tissue based criterion that applies equally in fresh and marine waters. EPA has explained in the preamble to the proposed rule why it is proposing to promulgate a criterion for methylmercury rather than mercury. See Appendix B for derivation of total mercury water column concentration equivalent to the methylmercury fish tissue concentration criteria values for use in evaluating reasonable potential. EPA recognizes that Maine has established interim mercury limits for permittees based on 38 MRS § 420, which prohibits the discharge of mercury and directs facilities to develop and implement pollution prevention practices to reduce and remove mercury discharges over time; 38 MRS § 413(11), which authorizes DEP to establish interim discharge limits to reduce the discharge of mercury and achieve ambient water quality criteria for mercury; and DEP Rule Chapter 519, which specifies that such interim mercury limits must be based upon and no less stringent statistically than past discharge levels, and that such interim limits shall not authorize any discharge of mercury that would cause or contribute to receiving water concentrations of mercury that exceed any water quality criteria published by EPA. As discussed further in Section 4.1.2, EPA has concluded that none of the permittees that discharge to waters in Indian lands or their tributaries discharges mercury at a level that would have a reasonable potential to cause or contribute to an exceedance of EPA's proposed methyl mercury criterion.

Section 4.1 details EPA's analysis of the cost impacts of the proposed HHC for consumption of water and organisms and of organisms only for waters in Indian lands.
Bacteria
EPA is proposing recreational criteria for waters in Indian lands that follow the recommended criteria EPA finalized in 2012 to protect the public from exposure to harmful levels of pathogens while participating in primary contact recreational activities. The proposed criteria incorporate three components: magnitude, duration, and frequency as follows:
In Class AA, Class A, Class B, Class C and Class GPA waters (i.e., freshwaters), Escherichia coli (E. coli) bacteria shall not exceed a geometric mean of 100 organisms per 100 ml obtained over a representative period of 30 days, nor shall a statistical threshold value of 320 organisms per 100 ml be exceeded by more than 10 percent of the time, in any 30-day interval.
In Class SA, Class SB, and Class SC waters (i.e., estuarine and marine waters), enterococcus bacteria shall not exceed a geometric mean of 30 organisms per 100 ml obtained over a representative period of 30 days, nor shall a statistical threshold value of 110 organisms per 100 ml be exceeded by more than 10 percent of the time, in any 30-day interval.
In addition, for Class AA, A and SA waters, EPA is proposing to include Maine's narrative criteria expression that bacteria content of these waters be as "naturally occurs." This supports Maine's intention that the waters be free of human caused pathogens, while the specific numeric criteria EPA proposes also provide protection for designated recreational uses in the event there are wild animal sources.
EPA is proposing that the bacteria criteria apply year round in waters in Indian lands. This differs from Maine's disapproved criteria, which do not apply from October 1 through May 14 in Class B, C, GPA, SB, and SC waters.
In Class SA shellfish harvesting areas, EPA is proposing that the number of total coliform bacteria in samples representative of the waters in shellfish harvesting areas shall not exceed a geometric mean for each sampling station of 70 MPN per 100 ml, with not more than ten percent of samples exceeding 230 MPN per 100 ml for the taking of shellfish. At present it appears that there are no Class SA waters in Indian lands, and therefore the proposed rule is not expected to result in incremental costs to permitted dischargers.
Of the 33 facilities that discharge to waters in Indian lands or their tributaries, 12 facilities discharge to Class B or C waters and have existing limits for E. coli bacteria, and 3 facilities discharge to Class SB or SC waters and have existing limits for fecal coliform bacteria to protect shellfishing. All of the permits apply the bacteria limits only between May 15 and September 30.
As summarized in Exhibit 3-2, which compares the baseline and proposed criteria, permit limits for dischargers to Class B waters are based on not exceeding criteria of an instantaneous level of 236 E. coli colonies/100 ml and geometric mean of 64 colonies/100 ml; and permit limits for dischargers to Class C waters are based on not exceeding criteria of an instantaneous level of 236 E. coli colonies/100 ml and geometric mean of 126 colonies/100 ml. Further, MEDEP considers dilution in setting instantaneous effluent limits, resulting in end-of-pipe permit limits that may be significantly greater than the 236 E. coli colonies/100 ml criterion (e.g., the permit for Millinocket, which discharges to Class C waters, sets limits of 126 colonies/100 ml (monthly) and 949 colonies/100 ml (daily maximum)).
The permits for discharges to Class SB and SC waters do not refer to Maine's enterococci criteria but rather set fecal coliform bacteria limits of a daily maximum of 50 colonies/100 mL and a monthly average limit of 15 colonies/100 mL (geometric mean) to meet shellfishing bacteria criteria. EPA does not endorse the absence of enterococci limits. However, for the purpose of this report, EPA believes it is reasonable to assume that the level of disinfection needed to meet the current fecal coliform bacteria limits will be adequate to meet EPA's proposed enterococci criteria.
Exhibit 3-2. Baseline and Proposed Bacteria Criteria
Waters
Baseline
Proposed
Class AA, A
Bacteria content as "naturally occurs."
Bacteria content as "naturally occurs."
E.coli 30-day geometric mean no more than 100/100 ml nor shall 320/100 ml be exceeded more than 10 percent of the time in any 30-day interval
Class B
From May 15-Sept 30, E. coli of human and domestic origin geometric mean no more than 64/100 ml and instantaneous level no more than 236/100 ml.
E.coli 30-day geometric mean no more than 100/100 ml nor shall 320/100 ml be exceeded more than 10 percent of the time in any 30-day interval
Class C
From May 15-Sept 30, E. coli of human and domestic origin geometric mean no more than 126 E.coli/100 ml and instantaneous level no more than 236/100 ml.
1.
SA
Bacteria content as "naturally occurs"
Bacteria content as "naturally occurs"
Enterococcus 30-day geometric mean no more than 30/100 ml nor shall 110/100 ml be exceeded more than 10 percent of the time in any 30-day interval
Total coliform geometric mean no more than 70 MPN/100 ml and no more than 10 percent of samples above 230 total coliform MPN/100 ml.
Class SB
From May 15-Sept 30, enterococcus of human and domestic animal origin geometric mean no more than 8/100 ml and instantaneous level no more than 54/100 ml
Total coliform or other specified indicator organism may not exceed criteria recommended under the National Shellfish Sanitation Program.
Enterococcus 30-day geometric mean no more than 30/100 ml nor shall 110/100 ml be exceeded more than 10 percent of the time in any 30-day interval.

Class SC
From May 15-Sept 30, enterococcus of human and domestic animal origin geometric mean no more than 14/100 ml and instantaneous level no more than 94/100 ml.
Total coliform or other specified indicator organism may not exceed criteria recommended under the National Shellfish Sanitation Program

EPA's review of discharge monitoring reports (DMRs) from 13 of the 15 facilities with existing bacteria limits shows that the facilities are generally able to achieve levels below the proposed criteria at the point of discharge, before accounting for any dilution. Daily maximum values rarely exceed the proposed statistical threshold value of 320 E. coli colonies/100 mL for discharges to Class B and C waters, and total fecal coliform values for dischargers to Class SB and SC waters exceeded the specified monthly limit at only one facility once out of 18 monitoring periods between 2011 and 2015. Accordingly, EPA does not expect that the proposed bacteria criteria for waters in Indian lands will result in incremental costs to permitted dischargers for the period of May 15  -  September 30. However, EPA proposes that the recreational criteria will apply year round. Therefore EPA expects that there could be incremental costs associated with additional disinfection occurring during the period of October 1  -  May 14. EPA estimated additional costs for chlorination, dechlorination and monitoring for the entire period of October 1 through May 14 at each plant that currently disinfects its effluent between May 15 and September 30. Section 4.2 describes this analysis.
Impacts of the proposed criteria on nonpoint sources depend on current levels of bacteria in waters in Indian lands that may be used for primary contact recreation. As discussed in Section 2.2.3, the very limited water quality monitoring data EPA found for waters in Indian lands show no measurements that would exceed the statistical threshold values for E. coli, irrespective of any duration or frequency considerations (maximum measurement was 64 colonies/100 ml; data are not sufficient to calculate statistical distribution). Only two samples were analyzed for enterococci levels, with a maximum of 71 colonies per 100 ml (data are not sufficient to calculate statistical distribution).
Ammonia
EPA is proposing to promulgate ammonia aquatic life ambient water quality criteria for waters in Indian lands. The national recommended criteria depend on both pH and temperature and, in the case of the acute criterion, on whether species of the Genus Oncorhynchus are present. For a pH of 7 and water temperature of 20 degrees Celsius, the acute criterion is 17 mg Total Ammonia Nitrogen (TAN) per liter (mg TAN/L) and the chronic criterion is 1.9 mg TAN/L (not to exceed 4.8 mg TAN/L as a 4-day average).
Similar to Maine's baseline acute criterion for ammonia, the proposed acute criterion depends on both pH and temperature. For a given pH, the proposed acute criterion is generally less stringent or equal to the baseline acute criterion for water temperatures less than approximately 15 degrees Celsius. The proposed acute criterion becomes more stringent (i.e., lower ammonia concentrations) than the baseline criterion as water temperatures increase. Exhibit 3-3 compares the baseline and proposed acute criteria for ammonia for different pH values and temperatures. Similar to Maine's baseline chronic criterion for ammonia, the proposed chronic criterion depends on both pH and temperature; however, the proposed chronic criterion is consistently lower (i.e., more stringent) than the baseline criterion (see Exhibit 3-4) across the range of pH and temperatures. For example, the proposed criterion for a temperature of 25ºC and pH of 7 is 1.4 mg/L as compared to 3 mg/L for the baseline criterion.
Exhibit 3-3. Comparison of Maine's baseline (solid line) and EPA's proposed (dashed lines) ammonia acute criteria for different temperatures[1]

1. Note that the criteria are very similar for the existing CMC as well as the proposed  CMC at 0-14 deg C and at 15 deg C (Oncorhynchus spp. Present), and as such, the lines may not appear distinct from one another.

Exhibit 3-4. Comparison of Maine's baseline (solid lines) and EPA's proposed (dashed lines) ammonia chronic criteria for different water temperatures.

Of the 33 facilities with permits to discharge to waters in Indian lands or their tributaries, two currently have effluent limits for ammonia. Another seven facilities are required to monitor for ammonia as part of a broader analytical chemistry monitoring requirement. The remaining 24 facilities, including several POTWs, have neither effluent limits nor monitoring requirements for ammonia, although some may be expected to have small amounts of ammonia in their effluent. For the purpose of this analysis, EPA assumed that effluents from these facilities do not have reasonable potential to exceed the proposed ammonia criteria in waters in Indian lands.
Both facilities with ammonia limits discharge to the Piscataquis River:
Dover-Foxcroft WWTP (ME0100501): The permit sets a limit of 279 lbs/day (monthly average) based on monitoring data, which showed a reasonable potential to exceed the chronic ambient water quality criteria (AWQC; 3.0 mg/L at temperature of 25ºC and pH 7.0) downstream from the plant. The limit applies during June 1-September 30. The limit reflects load allocation on the Piscataquis River at Milo among three dischargers.
Guilford-Sangerville (ME0102032): The permit sets a limit of 13 lbs/day (monthly average) based on the load allocation for the Piscataquis River at Milo.
A third facility discharging to the Piscataquis River (Milo, ME0100439) had its ammonia limit removed from the most recent permit following MEDEP's determination that the facility no longer had the potential to result in exceedances of the chronic AWQC for ammonia (3.0 mg/L at temperature of 25ºC and pH 7.0).
Review of analytical chemistry and priority pollutant scan data showed several other facilities with detected ammonia concentrations.
Section 4.1 details EPA's analysis of the cost impacts of the proposed ammonia criteria for fresh waters in Indian lands.
pH
Natural waters in Maine, as elsewhere in New England, could easily vary between 5.0-8.0 SU of pH for a variety of reasons (e.g., basin geology, buffering capacity, precipitation, and photosynthetic activity). MEPDES permits typically allow a wide range of pH levels for discharges, allowing them to accommodate discharges from plant operations or treatment units that might vary significantly in pH. Treatment of effluent to reduce metals can result in altered pH levels in the discharge. EPA's proposal to raise the lower value of the pH range from 6.0 to 6.5 SU could result in needed changes to facility operations in cases where existing treatment affects pH levels.
EPA reviewed data for six facilities that have permit limitations and detected effluent records for heavy metals (out of the total of 33 facilities discharging to waters in Indian lands or their tributaries). Five of these facilities can be expected to have little potential for costs based on their low flow, wastewater sources, and/or existing monitoring data. The remaining facility (Woodland Pulp) has a permit that allows for discharges of effluent within a wider pH range (5.0 to 9.0 SU) based on technology-based limits in Effluent Guidelines and Standards (ELGs) for the Pulp, Paper, and Paperboard Point Source Category (40 CFR 430). The facility adjusts the pH of its effluent before discharge and historical DMR data demonstrate that the facility has been able in the past to meet the proposed criterion. See Appendix D for summary of EPA's review.
Detailed information on neutralization methods employed by Woodland Pulp and their performance would be needed to evaluate the potential for additional costs related to treatment of acidic effluent. Given the limited information available and evidence that the facility already adjusts pH and achieves levels above 6.5, EPA assumed that any incremental costs would be minimal.
Temperature Criterion for Tidal Waters
MEDEP Chapter 582 establishes a not-to-exceed criterion of 85ºF outside of the discharge mixing zone in marine waters. Maine also limits discharges from causing the monthly mean of the daily maximum ambient temperatures in any tidal waterbody to be raised more than 4ºF at any time, or more than 1.5°F from June 1 to September 1 (summer months).
In contrast, EPA proposed criteria include a maximum cumulative increase in weekly average temperature from all artificial sources of 1°C (1.8° F) year round, relative to baseline temperature, and provided that the summer weekly maximum of 18°C (64.4° F) is not exceeded; and requires that the natural temperature cycles be maintained. Accordingly, adoption of EPA's proposed temperature criteria could affect discharge permit thermal limits outside of the summer months, particularly because discharge temperatures resulting in a departure of 4°F on a monthly basis would be greater than those associated with a 1.5°F increase on a weekly basis. It would also affect discharges that cause the receiving water to exceed the summer maximum criterion.
However, only four of the 33 dischargers to waters in Indian lands or their tributaries discharge into tidal or marine waters: Calais School (ME0102765), Washington County Community College (ME0102831), Passamaquoddy POTW (ME0100100773), and Calais POTW (ME0100129). The Calais POTW and the two schools discharge treated sanitary wastewater to the St. Croix River, and the Passamaquoddy POTW discharges to Passamaquoddy Bay. None of the facilities discharge heat. These discharges are not expected to have a noticeable effect on temperatures in the tidal waters near the Pleasant Point Reservation. Based on this assessment, EPA assumed there would be no incremental costs for the proposed temperature criterion for tidal waters.
Mixing Zone
EPA disapproval of Maine's mixing zone policy may affect dischargers for which MEDEP established mixing zones. Compared to the disapproved mixing zone policy, the proposed mixing zone policy provides greater protection for designated aquatic life uses by:
clarifying the extent to which criteria may be exceeded in a mixing zone;
specifying that mixing zone must be as small as necessary, and pollutant concentrations must be minimized and reflect the best practicable engineering design of the outfall to maximize initial mixing;
requiring the use of methodologies in EPA's "Technical Support Document for Water Quality-based Toxics Control";
prohibiting the use of a mixing zone for bioaccumulative pollutants and for bacteria; and
establishing a number of restrictions to protect designated uses, including requirements that the mixing zone not result in lethality to organisms passing through or within the mixing zone, and not endanger critical areas such as breeding and spawning grounds, habitat for threatened or endangered species, and areas with sensitive biota, shellfish beds, fisheries, and recreational areas.
EPA found only one permit that contains adjusted effluent limits based on a mixing zone (Woodland Pulp, with a mixing zone for heat). The implications for that discharger of changes in the mixing zone policy are uncertain, but could include the need to conduct more detailed assessments of thermal impacts, recalculate the spatial or volumetric limitations for the zone of initial dilution (ZID) and thermal mixing zone, and require zones of passage. A smaller available mixing zone resulting from the proposed rule may lead the discharger to seek a CWA section 316(a) thermal variance rather than having to meet otherwise applicable thermal limitations. To support such a variance request, the discharger would need to conduct a section 316(a) Demonstration Study during renewal of the discharge permit. Such field studies can require significant levels of effort. Further, if the thermal effluent variance request is denied, the discharger may be required to upgrade or install new technologies to reduce discharge thermal loading and/or modify discharge conditions or structures. Design, engineering and implementation of such new technologies or adoption of improved operational practices can represent major costs.
To understand the potential implications for the discharger, EPA reviewed information available for this facility. Exhibit 3-5 summarizes key information regarding the thermal mixing zone at this facility.
 Exhibit 3-5. Discharger with Thermal Mixing Zone Affecting Waters in Indian Lands
Facility
Permit Conditions
Woodland Pulp LLC
(ME 0001872)
1.  Thermal discharge to the St. Croix River with seasonal limits (June 1  -  September 30)
2.  Permit defines a zone of initial dilution (ZID) over a 5.3 mile segment of river (to Baring railroad trestle) and a mixing zone extending 4.0 mile downstream from the edge of the ZID (from Baring railroad trestle to Milltown dam)
3.  Thermal survey conducted by GPC in 1989 indicated >2[o]F increase below the discharge point. ME Division of Environmental and Assessment (ME DEA) developed QUAL2E model using GPC data to calibrate the model. The model predicted a temperature increase of 1.1[o]F at end of ZID. ME DEA and GPC concurred that separation of discharge impacts from natural diurnal temperature fluctuations was difficult and that it was preferable to establish a formal mixing zone.
4.  The 1996 WDL established the original average and daily maximum thermal load limitations and ZID and thermal mixing zone.
5.  The 1996 WDL stated that no testing shall be conducted for thermal violations within designated ZID or established mixing zone. The 1996 WDL also contained special conditions requiring the plant to investigate ways to reduce heat loads.
6.  Four cooling towers were installed in 1997. Plant ceased using two of them in 1998 due to operation and maintenance problems.
7.  2005 permit required continuous in-stream monitoring between June and September but requirements were discontinued in 2012.
8.  Based on its review of the monitoring report for 2012, MEDEP concluded that "the thermal discharge resulted in temperature greater than would be allowed under DEP's temperature rule, if not for the existence of a mixing zone where the rule does not apply"
Sources:
Woodland Pulp LLC: MEPDES Permit #ME0001872; Maine WDL Application #W002766-5N-J-R, June 28, 2014

Section 4.4 details EPA's analysis of the cost impacts of the proposed mixing zone policy for waters in Indian lands.
Proposed Dissolved Oxygen Criteria for All State Waters
The proposed rule includes the same year-round criteria for Class A fresh waters that Maine uses, but adds more protective DO criteria for spawning areas in winter months. Specifically, the proposed rule requires that the 7-day mean DO concentration be no less than 9.5 ppm (9.5 mg/L), and the 1-day minimum DO concentration be no less than 8 ppm (8.0 mg/L)  --  for spawning areas in winter months.
The proposed rule may potentially affect 26 facilities with draft or final permits to discharge in Class A waters. EPA's review of permits for the 26 facilities affected by the proposed DO criteria shows several facilities for which MEDEP determined a potential for impacts to DO levels in receiving waters and set daily minimum DO concentrations for the effluent. These limits are applicable from June 1[st] to September 30[th]. Because monitoring is limited to the period when the limits apply, no effluent monitoring data for DO were available for winter months. As described in Section 2.2.8, EPA also reviewed ambient monitoring data for Class A waters, but EPA noted that of the 193 samples collected by MEDEP on Class A waters (not all of which would have a permitted discharger), none were collected during the winter months.
According to Maine law, granting of discharge permits in Class A waters is predicated on the discharged effluent being equal to or better than the existing water quality of the receiving water (38 M.R.S §465(2.C)). This requirement means that in cases where ambient water quality is equal to or better than what the proposed criteria would require (i.e., ambient water quality is already above 8.0 mg/L daily minimum and 9.5 mg/L for the 7-day mean) during the winter months, the proposed criteria would not result in incremental costs to the facilities.
As discussed in Section 2.2.8, nonpoint sources are an important contributor to DO impairments by increasing organic loads into the streams. Effects of the proposed DO criteria for winter months on these nonpoint sources are difficult to assess given the lack of existing data. EPA assumed that these effects would be minimal given the limited scope of the proposal to Class A waters.
Proposed Phenol Criteria for State Waters Outside of Indian Lands
EPA disapproved the criterion for phenol (for the consumption of water and organisms), which was 10,514 ug/l, for Maine waters outside of Indian lands due to a mathematical error. EPA's proposed criterion of 4,000 ug/L corrects the mathematical error and is based on EPA's 2015 national recommended criterion but adjusted to use Maine's FCR of 32.4 g/day.
Very little data are available on ambient concentrations or discharges of phenol in Maine waters. Public data sources EPA reviewed showed no analytical results for phenol in surface waters. EPA's DMR data list only two facilities in Maine (Brunswick Graham Rd Landfill (ME0102113) and Presque Isle Landfill (MEU508088)) that monitor for, and report, total phenols in their effluent. Of these two dischargers, only the Brunswick Graham Rd Landfill facility had non-zero concentrations. The reported maximum effluent concentration (MEC) for this facility was 2.1 ug/L, which is below both the baseline and proposed criteria before accounting for dilution.
Based on this information, EPA concluded that the proposed criterion is unlikely to result in incremental costs.

Method for Estimating Potential Costs: Point Sources
This section describes the method for estimating the potential costs to point sources associated with compliance with the proposed criteria, including available data. Compliance costs for municipal and industrial point sources may result from changes to MEPDES permit requirements and associated effluent limitations. As discussed in Section 3, proposed criteria for pH and temperature (for waters in Indian lands), proposed criteria for phenol (for state waters outside Indian lands) and proposed criteria for DO (for all state waters) are not expected to result in incremental costs to permitted dischargers. The cost analysis, therefore, focuses specifically on the impacts of:
proposed HHC for waters in Indian lands (Section 4.1),
proposed bacteria criteria for waters in Indian lands (Section 4.2),
proposed aquatic life ammonia criteria for waters in Indian lands (Section 4.3), and
proposed mixing zone policy for waters in Indian lands (Section 4.4).
EPA notes that the analysis is based on information from publicly available data, permit fact sheets, and priority pollutant scans conducted in accordance with existing permits. While the analysis generally follows the approach a permit writer would use to evaluate and set discharge permit conditions, reliance on available data involves uncertainty and limitations not present during actual permit development, such as more site-specific data (e.g., ambient water quality samples, priority pollutant scans using lower detection limits). See Section 6.3 for further discussion of the uncertainty associated with the use of existing data.
Except as otherwise noted, the assumed life of capital investments is 20 years, and EPA used a discount rate of 3 percent for the main analysis. Results using a 7 percent discount rate are provided in Appendix E.
Costs from Proposed Human Health Criteria for Waters in Indian Lands
EPA estimated costs to municipal and industrial dischargers under the proposed criteria by estimating costs to each of the 33 facilities that discharge to waters in Indian lands or their tributaries. This section describes the reasonable potential analysis, identification of limits under the proposed criteria and comparison to baseline criteria, and estimation of costs to meet proposed criteria.
Unless otherwise noted, EPA updated all cost estimates to 2014 dollars.
Dischargers to Waters in Indian Lands or Tributaries
Factors that may affect the potential magnitude of compliance costs include effluent flow and type of facility. Larger flows are typically associated with the largest treatment costs, although per-unit costs may decrease due to economies of scale. A facility's industrial category may also be indicative of the potential to incur costs.
As described in Section 1.2, EPA determined that 33 facilities (major and non-major) discharge to waters in Indian lands or their tributaries. Exhibit 4-1 provides a summary of the facilities that discharge to waters in Indian lands or their tributaries. Appendix A provides additional information on these facilities.
EPA notes that almost all (29) facilities discharge to fresh waters, to which the proposed HHC for the consumption of water and organisms would apply. Some of these facilities discharge directly to the waters in Indian lands to which EPA's proposed criteria would apply. Many of the facilities, however, discharge upstream of the waters in Indian lands (including tributaries of such waters), and limits on those discharges would need to ensure that EPA's proposed criteria are met at the boundary of the waters in Indian lands, not at the point of discharge. Four facilities discharge to estuarine or marine waters, to which the HHC for the consumption of organisms only would apply. Only one of these (the Passamaquoddy POTW) discharges directly to waters in Indian lands to which EPA's proposed criteria would apply. The other three facilities (Calais School, Calais POTW, and Washington County Community College) discharge to the St Croix River significantly upstream of the waters in Indian lands at Pleasant Point.
Exhibit 4-1. Summary of Dischargers to Waters in Indian Lands or Their Tributaries
MEPDES Number
Facility Name
Facility Type
Receiving Surface Waters (Class)
Permitted Monthly Average Flow (MGD)
ME0101320
Baileyville POTW
POTW
St. Croix River (C)
0.6
ME0102784
Brownville
POTW
Pleasant River (B)
                                   no limit
ME0100129
Calais POTW
POTW
St. Croix River (SC/C[2])
1.5
ME0102765
Calais School
Other (school)
Penobscot River (SC)
0.013
ME0001104
Cobb State Fish Hatchery
Other (fish hatchery)
Cold Stream (A)
5.0
ME0023213
Covanta Maine
Industrial (biomass energy)
Penobscot River (B)
0.189
ME0036528
Dolby Hydro Project
Industrial (hydroelectric)
West Branch of the Penobscot River (C)
0.365
ME0102229
Dover-Foxcroft Water District
Utility (drinking water treatment)
Piscataquis River (B)
0.15
ME0100501
Dover-Foxcroft WWTP
POTW
Piscataquis River (B)
0.8
ME0036511
East Millinocket Hydro Project
Industrial (hydroelectric)
Penobscot River (C)
0.3024[1]
ME0000175
East Millinocket POTW
POTW
Penobscot River (C)
2.0
ME0036625
Eustis Hydro Project
Industrial (hydroelectric)
North Branch Dead River (A)
0.0072[1]
ME0001082
Grand Lake Stream Fish Hatchery
Other (fish hatchery)
Grand Lake Stream (A)
2.9
ME0102032
Guilford-Sangerville WWTF
POTW
Piscataquis River (B)
0.465
ME0101290
Houlton WWTF
POTW
Menuxdekeag River (B)
1.5
ME0036633
Howland Hydro Project
Industrial (hydroelectric)
Piscataquis River (B)
0.0014
ME0101788
Howland POTW
POTW
Penobscot River (B)
0.30
ME0101796
Lincoln Sanitary District
POTW
Penobscot River (B)
1.07
ME0036552
Mattaceunk Hydro Project
Industrial (hydroelectric)
Penobscot River (C)
0.144[1]
ME0102245
Mattawamkeag WWTF
POTW
Penobscot River (B)
0.09
ME0102695
Milford
Utility (combined sewer overflow)
Penobscot River (B)
                                  unspecified
ME0037371
Millinocket Hydro
Industrial (hydroelectric)
West Branch of the Penobscot River (C)
0.022
ME0100803
Millinocket POTW
POTW
West Branch of the Penobscot River (C)
1.34
ME0100439
Milo POTW
POTW
Piscataquis River (B)
0.39
ME0102211
Passamaquoddy Water District
Utility (drinking water treatment)
Boydon Stream (B)
0.045
ME0100773
Passamaquoddy Tribal Council
POTW
Passamaquoddy Bay (SB)
0.15
ME0101311
Penobscot Indian Nation
POTW
Penobscot River (B)
0.1
ME0002216
Tate and Lyle Ingredients
Industrial (food manufacturer)
Menuxdekeag River (B)
0.04
ME0102831
Washington County Community College
Other (college)
St. Croix River (SB)
0.0105
ME0036668
West Enfield Hydro Project
Industrial (hydroelectric)
Penobscot River (B)
0.403
ME0036668
Woodland Hydro
Industrial (hydroelectric)
St. Croix River (C)
0.194
ME0001872
Woodland Pulp
Industrial (pulp mill)
St. Croix River (C)
30
ME0022063
Woodland Pulp: North Site
Industrial (logging)
St. Croix River (C)
16.16
MGD = million gallons per day
POTW = publicly owned treatment works
WWTP = wastewater treatment plant
STP = sewage treatment plant
 1. The flow is a design maximum rather than an average monthly flow limitation.
 2. This permit authorizes discharges from the Calais POTW and four combined sewer overflows (CSOs) to Class SC waters and one CSO to Class C waters.

Reasonable Potential Analysis
For each facility, EPA conducted a reasonable potential analysis to determine whether there is reasonable potential for the effluent to cause or contribute to a water quality violation for any of the pollutants for which EPA is proposing new criteria. For consistency with state implementation procedures, EPA determined reasonable potential using an approach that is consistent with the procedures described in 06-096 CMR 530(3)(E) and U.S. EPA (1991); Section 3.3.2 and Table 3-2), as well as EPA's NPDES Permit Writer's Manual (U.S. EPA, 2010a), and reflecting the fact that, in some cases, the proposed criteria would not apply to the immediate receiving waters but instead would apply to waters in Indian lands downstream from the receiving waters.
EPA conducted the reasonable potential analysis for each proposed criterion and facility, using the last five years (October 2010 to October 2015) of priority pollutant scan monitoring data. Since these data are more recent than the effluent monitoring data used to establish limitations in the facilities' existing permits, it is possible for EPA's reasonable potential analysis to indicate reasonable potential under the baseline criteria even when there is no permit limit. However, as shown in the analyses for each permitted facility in Appendix A, there were no such cases.
Effluent monitoring data are a key input for determining reasonable potential. There were not sufficient and adequate data available for all facilities to perform reasonable potential analyses for all pollutants for which HHC are proposed. For example, MEDEP requires annual priority pollutant scans for only nine facilities out of the 33 facilities that discharge to waters in Indian lands or their tributaries. The remaining 24 facilities do not have monitoring requirements due to the facility classification or the nature of the discharge. Appendix A summarizes the status of these 24 facilities in more detail. Additionally, for the nine facilities with priority pollutant scan requirements, the associated scan reports did not provide data for all pollutants for which EPA is proposing HHC.
EPA did not assess reasonable potential for pollutants for which data were unavailable. Instead, EPA assumed that the facilities do not have the potential to discharge pollutants in quantities that could lead to exceedances of HHC. EPA considers this assumption to be reasonable given the rationale provided by MEDEP in permit fact sheets for not requiring monitoring in the first place; specifically the expectation that discharges from each of these facilities were unlikely to contain priority pollutants. While this determination was based on the potential to exceed Maine's baseline HHC, EPA assumes that the same conclusion would be reached when considering the potential to exceed the proposed criteria. Additional data would be needed to confirm or refute this finding under the proposed rule. EPA recognizes that this assumption does not account for the possibility of a pollutant being present in quantities below the reporting levels but above the proposed criteria.
For each facility with priority pollutant scan data available in the last five years, EPA identified each relevant pollutant that had at least one detected value (i.e., a measured concentration above the lab detection level). For the purpose of this analysis, for pollutants with only non-detects EPA assumed no reasonable potential, whereas for pollutants with at least one detected value, EPA assumed the value of any non-detects equal to half the detection limit stated in the scan report. EPA then calculated the number of observations and maximum and average effluent concentrations.
To determine whether a facility would have reasonable potential to exceed the proposed criteria for a pollutant, EPA multiplied the maximum concentration by a multiplier from US EPA (1991; Table 3-2; determined based on the number of observations and the coefficient of variation) and divided by the facility-specific harmonic mean dilution factor. As discussed earlier, the reasonable potential was evaluated at the point where the proposed criteria apply, i.e., the point where the discharge reaches waters in Indian lands, which may be downstream from the immediate receiving waters. For each facility, EPA determined whether the immediate receiving waters are in Indian lands, and if not, EPA obtained flow information for waters in Indian lands downstream from the discharge location and used the data to calculate the concentrations at that location. For example, for facilities discharging to the Piscataquis River, EPA determined whether the discharge would have reasonable potential to cause an exceedance above the proposed criteria at the confluence of the Piscataquis and Penobscot rivers, where flows from the Piscataquis River enter waters in Indian lands.
EPA added each facility's expected contribution to background concentrations present in the receiving water to calculate the total receiving water concentration (RWC), as shown in the equation below. To determine whether the facility would have reasonable potential to exceed a particular proposed criterion, EPA compared the RWC to the assimilative capacity of the receiving water, which was based on the proposed criterion and the receiving water mean harmonic flow. If the RWC exceeded the assimilative capacity, then the facility would have reasonable potential for that pollutant.
RWC=FlowR  x ConcR+FlowF  x ConcF xMult(FlowR+ FlowF)
where:
    RWC	=	The receiving water concentration including the background concentration and the facility's contribution (ug/L)
    FlowR	=	The harmonic mean flow of the receiving water in Indian lands (MGD) upstream of the discharge
    ConcR	=	The background concentration in the receiving water (upstream of discharge) (ug/L)
    FlowF	=	The facility average flow limitation (MGD)
    ConcF	=	The facility's maximum effluent concentration (ug/L)
    Mult	=	Multiplier from U.S. EPA (1991); based on number of observations and coefficient of variation
The RWC reflects the contribution of an individual facility to the receiving water. However, in some cases multiple dischargers affect the same water. In those cases, EPA evaluated reasonable potential to exceed the proposed criteria by accounting for the cumulative impacts of discharges. For example, if two dischargers that are very close to each other both discharge a particular pollutant, EPA allocated a share of the receiving water's assimilative capacity for that pollutant to each facility (based on historical average loading). In other cases, a facility's effluent may mix with that of other facilities further downstream; in such cases EPA also evaluated reasonable potential cumulatively at the most downstream location along waters in Indian lands. The equation below shows how EPA calculated the share for each facility.
Sharei=Flowi*Concii=1nFlowi*Conci
where:
    Sharei  	=	The share of the receiving water assimilative capacity for the pollutant that is allocated to facility i
    Flowi	=	Monthly average flow limitation for facility i
    Conci	=	Average effluent concentration of the pollutant for facility i
    n		= 	Number of facilities discharging the pollutant to the given receiving water
Exhibit 4-2 illustrates this by showing facilities discharging to the Penobscot River or its tributaries upstream of Indian Island. For these facilities, EPA looked at the potential for any individual facility to exceed the proposed criteria at the point where its flow enters Indian lands (either at the point of discharge for facilities on the Penobscot River, or at the confluence of the Piscataquis River and the Penobscot River for facilities on the Piscataquis River), as well as the potential for the combination of all dischargers to exceed the proposed criteria at the location of the most downstream facility on the Penobscot River (e.g., Penobscot Housing Indian Island) discharging the pollutant of concern. In both cases, EPA considered the cumulative impact of the discharger's effluent combined with the effluent of all upstream dischargers.
Exhibit 4-2: Facilities discharging to the Penobscot River in Indian lands or its tributaries.

Note that EPA's approach for determining reasonable potential increases the likelihood of finding reasonable potential and setting more stringent effluent limits, relative to MEDEP's procedure.
According to 06-096 CMR 530(3)(F)(3), if all values are below Maine's reporting limits, then the facility is deemed to have no reasonable potential to exceed criteria. However, in many cases, actual laboratory detection levels are more sensitive than Maine's reporting limits. For this analysis, EPA used the laboratory's stated detection limit in lieu of Maine's reporting limit to determine reasonable potential.
Additionally, it is unclear whether MEDEP typically includes consideration of background concentrations in determining reasonable potential. None of the permits reviewed in preparing this Economic Analysis discussed the background concentrations for toxic pollutants (although several permits did account for background nutrient concentrations). For the purpose of this analysis, EPA incorporated consideration of the background concentration of pollutants when comparing facility contributions to receiving waters. In the absence of monitoring data for reference sites, for the purposes of this report, EPA followed Maine's practice (see 06-096 CMR 530(4)(C)) of assuming background levels equal to 10 percent of the criteria. This assumption tends to overstate the potential for exceeding the water quality criterion, relative to assuming no background level.
Appendix A provides facility-specific reasonable potential results under the baseline and proposed rule scenarios and additional information on the specific data sources used for each facility. Exhibit 4-3 summarizes, for each facility, the pollutants with detected effluent data (i.e., the pollutants for which EPA conducted a reasonable potential analysis), and the pollutants for which EPA determined that the facility has reasonable potential to exceed baseline or proposed criteria for waters in Indian lands. One facility has a reasonable potential to exceed one proposed criterion.
Exhibit 4-3. Summary of Dischargers with Detected Effluent Data and Reasonable Potential Analysis
MEPDES Number
Facility Name
Pollutants with Detected Effluent Data Available[1]
Pollutants with Reasonable Potential
ME0101320
Baileyville POTW
Mercury
None
ME0102784
Brownville
None
None
ME0100129
Calais POTW
Cyanide, dichloro-bromomethane, mercury, toluene
None
ME0102765
Calais School
None
None
ME0001104
Cobb State Fish Hatchery
None
None
ME0023213
Covanta Maine
None
None
ME0036528
Dolby Hydro Project
None
None
ME0102229
Dover-Foxcroft Water District
None
None
ME0100501
Dover-Foxcroft WWTP
Mercury
None
ME0036511
East Millinocket Hydro Project
None
None
ME0000175
East Millinocket POTW
None
None
ME0036625
Eustis Hydro Project
None
None
ME0001082
Grand Lake Fish Hatchery
None
None
ME0102032
Guilford-Sangerville WWTF
Antimony, mercury, phenol
None
ME0101290
Houlton WWTF
Mercury
None
ME0036633
Howland Hydro Project
None
None
ME0101788
Howland POTW
Mercury
None
ME0101796
Lincoln Sanitary District
Cyanide, mercury
None
ME0036552
Mattaceunk Hydro
None
None
ME0102245
Mattawamkeag
None
None
ME0102695
Milford
None
None
ME0037371
Millinocket Hydro