Permit No.: COS 000008 County: Denver AUTHORIZATION TO DISCHARGE UNDER THE COLORADO DISCHARGE PERMIT SYSTEM In compliance with the provisions of the Colorado Water Quality Control Act, ( 25 8 101 et seq., CRS, 1973 as amended) and the Federal Water Pollution Control Act, as amended ( 33 U. S. C. 1251 et seq.; the " Act") the CITY AND COUNTY OF DENVER is authorized to discharge from Denver International Airport, located in the NW 1/ 4 of Sec. 21, T2S, R65 W, 6th P. M., to Second Creek, Third Creek and Box Elder Creek, in accordance with effluent limitations, monitoring requirements and other conditions set forth in Part I and II hereof. All discharges authorized herein shall be consistent with the terms and conditions of this permit.

The applicant may demand an adjudicatory hearing within thirty ( 30) days of the issuance of the final permit determination, per the Colorado Discharge Permit System Regulations, 61.7( 1). Should the applicant choose to contest any of the effluent limitations, monitoring requirements or other conditions contained herein, the applicant must comply with Section 24 4 104 CRS and the Colorado Discharge Permit System Regulations. Failure to contest any such effluent limitation, monitoring requirement, or other condition, constitutes consent to the condition by the Applicant.

This permit and the authorization to discharge shall expire at midnight, July 31, 2006.

Issued and Signed this day of COLORADO DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT J. David Holm, Director Water Quality Control Division Permit No. COS 000008 TABLE OF CONTENTS PART I ......................................................................................................................................................................................................................................... 4 A. TERMS AND CONDITIONS..................................................................................................................................................................................... 4 1. Effluent Limitations.............................................................................................................................................................................................. 4 2. Compliance Schedule........................................................................................................................................................................................... 5 B. MONITORING REQUIREMENTS ........................................................................................................................................................................... 6 1. Frequency and Sample Type ................................................................................................................................................................................ 6 2. Monitoring Conditions ......................................................................................................................................................................................... 9 3. Representative Sampling.................................................................................................................................................................................... 10 4. Analytical and Sampling Methods for Monitoring............................................................................................................................................. 10 5. Changes to Monitoring Requirements ............................................................................................................................................................... 10 C. STORMWATER MANAGEMENT PLAN  CONTENTS AND REQUIREMENTS .......................................................................................... 11 1. Industrial Activity Description............................................................................................................................................................................ 11 2. Site Map.............................................................................................................................................................................................................. 11 3. Stormwater Management Controls .................................................................................................................................................................... 11 a. SWMP Administrator................................................................................................................................................................................. 11 b. Identification of Potential Pollutant Sources and Best Management Practices......................................................................................... 11 c. Sampling Information ................................................................................................................................................................................ 12 d. Preventive Maintenance............................................................................................................................................................................. 12 e. Good Housekeeping................................................................................................................................................................................... 12 f. Spill Prevention and Response Procedures................................................................................................................................................ 12 g. Employee Training..................................................................................................................................................................................... 12 h. Identification of Discharges other than Stormwater .................................................................................................................................. 12 4. Comprehensive Inspections................................................................................................................................................................................ 13 5. Consistency with Other Plans ............................................................................................................................................................................ 13 D. BASIC TERMS AND CONDITIONS...................................................................................................................................................................... 13 1. General Limitations ............................................................................................................................................................................................ 13 2. Best Management Practices ( BMPs) ................................................................................................................................................................. 13 3. Additional SWMP Requirements....................................................................................................................................................................... 15 4. Prohibition of Non stormwater Discharges ....................................................................................................................................................... 16 5. Releases in Excess of Reportable Quantities ..................................................................................................................................................... 16 6. Facility Inspections ............................................................................................................................................................................................. 16 7. SWMP Availability............................................................................................................................................................................................. 17 E. DEFINITIONS OF TERMS....................................................................................................................................................................................... 17 F. REPORTING REQUIREMENTS............................................................................................................................................................................. 17 1. Annual Report .................................................................................................................................................................................................... 17 2. Additional Reporting .......................................................................................................................................................................................... 18 3. Reporting to Municipality................................................................................................................................................................................... 18 4. Routine Reporting of Data ................................................................................................................................................................................. 18 5. Records ............................................................................................................................................................................................................... 19 6. Signatory and Certification Requirements ......................................................................................................................................................... 19 G. FIGURES.................................................................................................................................................................................................................... 21 PART II...................................................................................................................................................................................................................................... 26 A. NOTIFICATION REQUIREMENTS ....................................................................................................................................................................... 26 1. Notification to Parties ......................................................................................................................................................................................... 26 2. Change in Discharge .......................................................................................................................................................................................... 26 3. Special Notifications  Definitions...................................................................................................................................................................... 26 4. Noncompliance Notification .............................................................................................................................................................................. 27 5. Other Notification Requirements ....................................................................................................................................................................... 27 6. Bypass Notification ............................................................................................................................................................................................ 28 7. Upsets ................................................................................................................................................................................................................. 28 8. Discharge Point .................................................................................................................................................................................................. 29 9. Proper Operation and Maintenance ................................................................................................................................................................... 29 10. Minimization of Adverse Impact........................................................................................................................................................................ 29 11. Removed Substances.......................................................................................................................................................................................... 29 12. Submission of Incorrect or Incomplete Information .......................................................................................................................................... 29 13. Bypass................................................................................................................................................................................................................. 29 14. Reduction, Loss, or Failure of Treatment Facility.............................................................................................................................................. 30 B. RESPONSIBILITIES................................................................................................................................................................................................. 30 1. Inspections and Right to Entry........................................................................................................................................................................... 30 2. Duty to Provide Information .............................................................................................................................................................................. 31 3. Transfer of Ownership or Control...................................................................................................................................................................... 31 4. Availability of Reports ........................................................................................................................................................................................ 31 5. Modification, Suspension, Revocation, or Termination of Permits By the Division ........................................................................................ 31 6. Oil and Hazardous Substance Liability .............................................................................................................................................................. 34 7. State Laws .......................................................................................................................................................................................................... 34 8. Permit Violations................................................................................................................................................................................................ 34 9. Property Rights................................................................................................................................................................................................... 34 10. Severability ......................................................................................................................................................................................................... 34 11. Renewal Application .......................................................................................................................................................................................... 34 12. Confidentiality.................................................................................................................................................................................................... 34 13. Fees..................................................................................................................................................................................................................... 34 14. Duration of Permit.............................................................................................................................................................................................. 35 15. Section 307 Toxics............................................................................................................................................................................................. 35 16. Antibacksliding................................................................................................................................................................................................... 35 17. Effect of Permit Issuance ................................................................................................................................................................................... 36 PART I A. TERMS AND CONDITIONS 1. Discharge Points a. Beginning no later than the effective date of this permit and lasting through July 31, 2006, the permittee is authorized to discharge from: the E outfall to Third Creek at pond T 239 ( 39.895900 lat/ 104.745944 long); the outfall to Second Creek immediately north of Pena Boulevard, ( 38.37264 lat/ 104.733040 long); Runway 35R, the outfall to Hayesmount Tributary immediately downstream of the runway ( 39.854736 lat/ 104.640416 long); Sub basin C+, the monitoring station on Third Creek, west of runway 35R ( 39.5157501 lat/ 104.422252 long); Runway 26, the outfall to Box Elder Creek at the east end of runway 8/ 26, just inside the security fence ( 39.877168 lat/ 104.613424 long); Hayesmount, the outfall to the Denver Hudson Canal, east of the Fire Training Facility, on the north side of runway 8/ 26, between taxiways R7 and R8 ( 39.879640 lat/ 104.653216 long); Barr Lake Drainage, the outfall to Barr Lake Drainage channel, just west of runway 34, between taxiways F9 and F10 ( 39.892236 lat/ 104.685328 long); Runway 7/ 25, the outfall to Second Creek at the southwest corner of the runway ( 39.840152 lat/ 104.727008 long), and Runway 34L, the outfall to Third Creek at the south end of the runway ( 39.854072 lat/ 104.6932 long) ( see Figure 5, Part I. G of the permit). There shall be no discharge of floating solids.

AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part I Page No. 5 Permit No. COS 000008 A. TERMS AND CONDITIONS b. Discharges caused by natural conditions: The Division may take enforcement action for a discharge caused by a natural event, that exceeds the permit requirements defined in this permit, unless the permittee demonstrates through properly documented operating logs, or other relevant evidence including but not limited to National Weather Service reports, that:

the discharge was caused by severe natural conditions ( tornadoes, widespread flooding, earthquakes, or other similar natural conditions);

there were no feasible alternatives to the discharges, such as the use of auxiliary treatment facilities, retention of untreated wastewater, reduction of inflow and infiltration, or use of adequate backup equipment. This condition is not satisfied if, in the exercise of reasonable engineering judgment, the permittee should have installed auxiliary or additional collection system components, wastewater treatment facilities, adequate backup equipment, or should have reduced inflow or infiltration;

the permittee provided adequate notification to the Division as outlined in paragraph c. above, including information that the discharge meets the conditions of this provision; and the permittee submitted a follow up report to the Division containing monitoring results for the discharge within 30 days after receiving analytical results for required monitoring of pollutants in the discharge.

2. Spent Aircraft Deicing Fluid ( ADF) Management System The permittee shall provide estimates of the capture efficiency of the spent ADF management system. The estimates shall provide an annual summary ( by deicing season) of the total amount ( on a mass basis) of ADF used, the amount of ADF collected, and of the total volume collected, an estimate of the amount recycled versus discharged at Metro. These estimates shall be included in the Annual Report ( see Part I. F. 1).

See Part I. E for additional definitions.

3. Compliance Schedules a. As per the Water Quality Study ( see discussion, Section V. B. 2 of the Rationale), and as modified by various correspondence and the final construction plans ( submitted to the Division on July 12, 2001), DIA will complete the following construction projects by the dates indicated:

1) Modification of collection system to collect snowmelt and additional surface and subsurface flows, to be completed by December 31, 2002. b/

2) Increased capacity of the dirty water conveyance system, and construction of at least 22 million gallons of new industrial stormwater pond capacity for the collection of dirty stormwater, to be implemented as indicated in Table 1, below.

The Division has approved the final construction plans, and so all terms and conditions of the plans, including but not limited to the compliance schedule, are automatically conditions of this permit.

The permittee shall complete the specified construction activities by December 31, 2002, in accordance with the following schedule of compliance, as approved by the Division.

AMENDED: May 1, 2002 EFFECTIVE: June 1, 2002 AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part I Page No. 6 Permit No. COS 000008 A. TERMS AND CONDITIONS Table 1  Compliance Schedule  Construction Activity Deadline Notice to Proceed for design contract July 21, 1999 ( completed)

Design complete September 15, 2000 ( completed)

Notice to Proceed for construction contract February 1, 2001 ( completed)

Construction complete and system start up November 30, 2002 Facility fully operational December 31, 2002 b/

b/ This date may be extended by the Division if insufficient precipitation is received by then to allow for a full operational testing of the new facilities.

b. The permittee shall complete the specified activities by April 1, 2003, in accordance with the following schedule of compliance, as approved by the Division.

Table 2  Compliance Schedule   Receiving water study Activity Deadline Draft study work plan completed March 30, 2001 ( completed)

Final study work plan completed July 1, 2001 ( completed)

Data Collection completed December 31, 2002 Study completed, report submitted to Division April 1, 2003 The permittee submitted a study work plan to the Division on June 29, 2001. The plan includes data collection and analysis, reviewing the findings with the Division and EPA, and submitting a final report.

Once the Division has approved the final study work plan, all terms and conditions of the plan, including but not limited to the compliance schedule, will automatically become conditions of this permit.

The results of the initial study may indicate the need for additional phases of study; in that case, the additional phases will automatically be included in the permit as compliance schedule items.

No later than 14 calendar days following each date identified in the above schedules of compliance, the permittee shall submit either a report of progress or, in the case of specific actions being required by identified dates, a written notice of compliance or noncompliance, any remedial actions taken, and the probability of meeting the next scheduled requirement.

Amended______________________________ Effective______________________________ Part I Page No. 7 Permit No. COS 000008 B. MONITORING REQUIREMENTS 1. Frequency and Sample Type The permittee shall monitor all effluent parameters at the following frequencies. Such monitoring will begin immediately and last for the life of the permit unless otherwise noted. The results of such monitoring shall be reported on the Discharge Monitoring Report form ( See Part I. F.).

Self monitoring sampling by the permittee for compliance with the monitoring requirements specified below shall be performed at the indicated locations. See Figure 5, and Section II. F of the Rationale for a detailed description of the outfalls.

a. Biological Monitoring 1) Discharge Points: E monitoring station. See Figure 5, Part I. G.

Effluent Parameter Measurement Frequency Sample Type Fish Survey Once/ permit term, September 2004 Grab b. Wet Weather Monitoring 1) Discharge Points: Sub basin A outfall; Sub basin C outfall; Sub basin D outfall; Runway 34L outfall. See Figure 5, Part I. G.

Effluent Parameter Measurement Frequency c/ Sample Type Chemical Oxygen Demand, mg/ l Once/ 2 Months Grab Dissolved Oxygen, mg/ l Once/ 2 Months Grab Oil and Grease, mg/ l Once/ 2 Months Visual d/ pH, s. u. Once/ 2 Months Grab Total Suspended Solids, mg/ l Once/ 2 Months Grab Propylene Glycol, mg/ l Once/ 2 Months Grab BOD5, mg/ l Once/ 2 Months Grab Nitrate plus Nitrite, as N, mg/ l Once/ 2 Months ( Sub basin A only) Grab Total Kjeldahl Nitrogen ( TKN), as N, mg/ l Once/ 2 Months Grab Flow, MGD Once/ 2 Months Instantaneous or Grab AMENDED: May 1, 2002 EFFECTIVE: June 1, 2002 AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part I Page No. 7a Permit No. COS 000008 B. MONITORING REQUIREMENTS 2) Discharge Points: Runway 35R ( Hayesmount Tributary immediately downstream of the runway). See Figure 5, Part I. G.

Effluent Parameter Measurement Frequency Sample Type Chemical Oxygen Demand, mg/ l Once/ 6 Mos Grab Dissolved Oxygen, mg/ l Once/ 6 Mos Grab pH, s. u. Once/ 6 Mos Grab BOD5, mg/ l Once/ 6 Mos Grab Propylene Glycol, mg/ l Once/ 6 Mos Grab Oil and Grease, mg/ l Once/ 6 Mos Visual d/ Total Suspended Solids, mg/ l Once/ 6 Mos Grab Flow, MGD Once/ 6 Mos Instantaneous or Grab c/ For sampling once/ 2 months, the two month periods shall be October/ November, December/ January, etc. Samples shall be taken at least one week apart. d/ See also Part I. B. 1. e of the permit.

AMENDED: May 1, 2002 EFFECTIVE: June 1, 2002 AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part I Page No. 10a Permit No. COS 000008 B. MONITORING REQUIREMENTS b. Dry Weather Monitoring Monitoring is required for the following parameters whenever, during the inspection of outfalls, the DIA staff observes or suspects an illicit discharge. Samples will be required at least once during each such instance of discharge. Additional parameters may be added to the initial screening, depending upon the nature of the discharge and attendant conditions.

1) Industrial Areas: Deicing Activities Effluent Parameter Sample Type Oil and Grease, mg/

Grab and Visual pH, s. u. Grab Temperature, oF Grab Chemical Oxygen Demand, mg/

Grab Propylene Glycol, mg/

Grab 2) Industrial Areas: Concourse Activities Effluent Parameter Sample Type Oil and Grease, mg/

Grab and Visual pH, s. u. Grab Temperature, oF Grab Specific Conductivity,  mhos Grab Propylene Glycol, mg/

Grab Chemical Oxygen Demand, mg/

Grab Fecal Coliform, #/ 100 ml Grab Total Petroleum Hydrocarbons ( Jet Fuel), mg/

Grab Amended______________________________ Effective______________________________ Part I Page No. 10a Permit No. COS 000008 B. MONITORING REQUIREMENTS 3) Industrial Areas: Hangars, Maintenance, Ground Services Equipment, Vehicle Storage, and Cargo Activities Effluent Parameter Sample Type Oil and Grease, mg/ l Grab and Visual pH, s. u. Grab Temperature, oF Grab Specific Conductivity,  mhos Grab Propylene Glycol, mg/ l Grab Chemical Oxygen Demand, mg/ l Grab Total Petroleum Hydrocarbons ( Jet Fuel), mg/ l Grab d. Diversion Mode Sampling 1) Diversion Area( s)

Effluent Parameter Sample Type Oil and Grease, mg/ l Grab and Visual pH, s. u. Grab Propylene Glycol, mg/ l Grab Chemical Oxygen Demand, mg/ l Grab Total Petroleum Hydrocarbons ( Jet Fuel), mg/ l Grab e. Oil and Grease Monitoring For every outfall with visual oil and grease monitoring, in the event an oil sheen or floating oil is observed, a grab sample shall be collected, analyzed, and reported on the appropriate DMR. In addition, corrective action shall be taken immediately to mitigate the discharge of oil and grease. A description of the corrective action taken must be included with the DMR.

2. Monitoring Conditions  Wet Weather Sampling   Required Quarterly and Semi Annual Sampling Only The requirements in this section shall only apply to the monitoring requirements outlined in Part I. B. 1. b. 1, 2 and 3, for those parameters where the required measurement frequency is Quarterly or Semi Annual .

a. Additional Information: The following additional information is required for each sampling event:

 the date and duration ( in hours) of the storm event( s) sampled;  rainfall measurements or estimates ( in inches) of the storm event which generated the sampled runoff;  the duration between the storm event sampled and the end of the previous measurable ( greater than 0.1 inch rainfall) storm event;  an estimate of the size of the drainage area ( in square feet) and an estimate of the runoff coefficient of the drainage area ( e. g. low ( under 40%), medium ( 40% to 65%) or high ( above 65%)); and  an estimate of the total volume ( in gallons) of the discharge sampled.

b. Sampling Procedures: For facilities with holding ponds or other impoundments, sampling shall be performed at the outlet from the pond. If no discharge from the pond to surface waters occurs, then no sampling is necessary.

All such samples shall be collected from the discharge resulting from a storm event that is greater than 0.1 inches in magnitude and that occurs at least 72 hours from the previously measurable ( greater than 0.1 inch rainfall) storm event.

AMENDED: May 1, 2002 EFFECTIVE: June 1, 2002 AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part I Page No. 10a Permit No. COS 000008 B. MONITORING REQUIREMENTS The storm water sample shall be representative of the " first flush" of storm water runoff. A sample shall be collected in the first 30 minutes of discharge, or as soon thereafter as practicable. When sampling snow melt and deicing or anti icing events, best professional judgment shall be used for when to collect a representative sample.

c. Fish Survey: A fish survey will be conducted at E monitoring station once during the permit term, in September 2004 ( see Part I. A. 1. a of the permit). The goal of the survey will be to determine the presence of fish, which would demonstrate fish community persistence. The following protocols will be used in conducting the fish survey:   Sampling will occur in September;   Sampling will occur in the reach at monitoring point E using a seine of an appropriate mesh size to capture adult fathead minnow;   Appropriate sampling protocols/ measurements will be performed to allow the calculation of fish density ( number of fish/ square meter); and   Captured fish will be weighed and measured before being returned to the stream.

The above protocols may be modified by the Division upon good cause presented by the permittee.

3. Representative Sampling Samples and measurements taken as required herein shall be representative of the volume and nature of the monitored discharge. All samples shall be taken at the monitoring points specified in this permit and, unless otherwise specified, before the effluent joins or is diluted by any other wastestream, body of water, or substance. Monitoring points shall not be changed without notification to and approval by the Division.

If the permittee monitors at the point of discharge any pollutant limited by the permit more frequently than required by the permit, using approved test procedures or as specified in the permit, the result of this monitoring shall be included in the calculation and reporting of data to the Division.

4. Analytical and Sampling Methods for Monitoring The permittee shall install, calibrate, use and maintain monitoring methods and equipment, including biological and indicated pollutant monitoring methods. All sampling shall be performed by the permittee according to specified methods in 40 C. F. R. Part 136; methods approved by EPA pursuant to 40 C. F. R. Part 136; or methods approved by the Division, in the absence of a method specified in or approved pursuant to 40 C. F. R. part 136. The analytical method selected for a parameter shall be the one that can measure the lowest detected limit for that parameter unless the permit limitation or stream standard for those parameters not limited, is within the testing range of another approved method. When requested in writing, the Division may approve an alternative analytical procedure or any significant modification to an approved procedure.

When the most sensitive analytical method which complies with this part, has a detection limit greater than or equal to the permit limit, the permittee shall report " less than ( the detectable limit)," as appropriate. Such reports shall not be considered as violations of the permit limit.

5. Changes to Monitoring Requirements For the sampling points listed in Part I. B. 1. a of the permit ( Wet Weather Monitoring), the sampling frequencies for Oil and Grease, pH, Acetate and Total Suspended Solids could be reduced in the event that DIA can provide adequate justification, based on each of the following items:

AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part I Page No. 10a Permit No. COS 000008 B. MONITORING REQUIREMENTS a. The permittee can provide at least two years of sampling data for the facility ( for each discharge point where sampling is required), for each of the parameters listed above. ( The samples must be from at least two different calendar years, and taken in 1998 or after.) A summary of all available monitoring data should be included in the amendment request, whether or not it was previously submitted to the Division.

b. The industrial activities at the site ( such as materials handling and storage, chemical use, waste disposal practices, erosion controls, and other types of industrial activities as defined in Part I. C. 3. b of the permit) have not changed since the samples were taken ( and are not expected to), in any way that could have an adverse impact on stormwater quality.

c. The sample results for the parameters listed above do not demonstrate any problems with stormwater quality. The permittee may compare their data with other water quality data, such as EPA's list of stormwater permit benchmarks from the multisector permit, or the federal Nationwide Urban Runoff Program ( NURP) data.

The Division will make a determination on the merits of the amendment request within 45 days of receipt. If the request is deemed adequate, the permittee will be notified and their permit amended to change the sampling requirement for the outfall( s) in question, for the remainder of the permit term. If the request is not considered adequate, the permittee shall be notified of the reason for the Division's determination. The permittee will also be able to re petition the Division after another year of sampling data has been obtained.

AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part I Page No. 11 Permit No. COS 000008 C. STORMWATER MANAGEMENT PLAN  CONTENTS AND REQUIREMENTS A SWMP shall be developed for each facility covered by this permit, and submitted to the Division. SWMPs shall be prepared in accordance with good engineering practices. ( The plan need not be completed by a registered engineer.)

The plan shall identify potential sources of pollution which may reasonably be expected to affect the quality of stormwater discharges associated with industrial activity from the facility. In addition, the plan shall describe and ensure the implementation of practices which are to be used to reduce the pollutants in stormwater discharges associated with industrial activity at the facility and to assure compliance with the terms and conditions of this permit.

DIA must implement the provisions of the SWMP required under this part as a condition of this permit. The Division reserves the right to review the plan, and to require additional measures to prevent and control pollution as needed.

The SWMP shall include the following items, at a minimum:

1. Industrial Activity Description The plan shall provide a narrative description of the industrial activity taking place at the site.

2. Site Map The plan shall include a site map indicating an outline of the drainage area of each stormwater outfall ( to the extent possible), each existing structural control measure to reduce pollutants in stormwater runoff, and surface water bodies.

3. Stormwater Management Controls Each facility covered by this permit shall develop a description of stormwater management controls appropriate for the facility, and implement such controls. The appropriateness and priorities of controls in a plan shall reflect identified potential sources of pollutants at the facility. The description of stormwater management controls shall address the following minimum components, including a schedule for implementing such controls:

a. SWMP Administrator: The SWMP shall identify a specific individual( s) within the plant organization who is responsible for developing the SWMP and assisting the plant manager in its implementation, maintenance, and revision. The activities and responsibilities of the administrator shall address all aspects of the facility's SWMP.

b. Identification of Potential Pollutant Sources and Best Management Practices: The SWMP shall identify potential sources of pollutants at the site, and assess the potential of these sources to contribute pollutants to stormwater discharges associated with industrial activity. The SWMP must also describe appropriate Best Management Practices ( BMPs) to reduce the potential of these sources to contribute pollutants to stormwater discharges.

At a minimum, each of the following shall be evaluated for the reasonable potential for contributing pollutants to runoff:

 Loading and unloading operations  Outdoor storage activities  Outdoor manufacturing or processing activities  Significant dust or particulate generating processes  On site waste disposal practices  The presence of salt piles  SARA Title III Section 313 Water Priority Chemicals  Areas where significant spills and significant leaks of toxic or hazardous substances have occurred at the facility from three years prior to permit certification to the time of SWMP preparation Factors to consider include the toxicity of chemicals; quantity of chemicals used, produced, or discharged; the likelihood of contact with stormwater; and history of significant leaks or spills of toxic or hazardous substances. Part I Page No. 12 Permit No. COS 000008 C. STORMWATER MANAGEMENT PLAN  CONTENTS AND REQUIREMENTS The description of the BMPs shall include:

1) Stormwater diversion: Describe how and where stormwater will be diverted away from industrial areas to prevent stormwater contamination.

2) Materials handling and spill prevention: Where materials can impact stormwater runoff, existing practices that reduce the potential for contamination shall be described. For example, materials shall be stored and handled in covered areas to prevent contact with stormwater, and chemicals shall be stored within berms or secondary containment devices to prevent leaks and spills from entering stormwater runoff.

3) Sediment and erosion prevention: The plan shall identify areas which, due to topography, activities, or other factors, have a high potential for significant soil erosion, and identify measures taken to limit erosion.

4) Other pollution prevention measures: The plan shall identify any other structural and non structural measures for stormwater quality control on site.

In each case where stormwater pollution potential exists, appropriate preventive measures must be taken and documented.

c. Sampling Information: The plan shall include a summary of any existing discharge sampling data describing pollutants in stormwater discharges, and a description of each proposed sampling point.

d. Preventive Maintenance: A preventive maintenance program is required, and shall involve inspection and maintenance of stormwater management devices ( cleaning oil/ water separators, catch basins, etc.) as well as inspecting and testing plant equipment and systems to uncover conditions that could cause breakdowns or failures resulting in discharges of pollutants to surface waters.

e. Good Housekeeping: Good housekeeping requires the maintenance of a clean, orderly facility. This part of the SWMP shall address cleaning and maintenance schedules, trash disposal and collection practices, grounds maintenance, etc.

f. Spill Prevention and Response Procedures: Areas where potential spills can occur, and their accompanying drainage points, shall be identified clearly in the SWMP. Where appropriate, specifying material handling procedures and storage requirements in the plan shall be considered. Procedures for cleaning up spills shall be identified in the plan and made available to the appropriate personnel. The necessary equipment to implement a clean up shall be available to personnel.

g. Employee Training: Employee training programs shall inform personnel at all levels of responsibility ( who are involved in industrial activities that may impact stormwater runoff) of the components and goals of the SWMP. Training shall address topics such as spill response, good housekeeping and material management practices. The SWMP shall identify periodic dates for such training. Contractor or temporary personnel shall be informed of plant operation and design features in order to prevent discharges or spills from occurring.

h. Identification of Discharges other than Stormwater: The stormwater conveyance system on the site shall be evaluated for the presence of discharges other than stormwater. The SWMP shall include a description of the results of any evaluation for the presence of discharges other than stormwater, the method used, the date of the evaluation, and the on site drainage points that were directly observed during the evaluation.

A number of discharges other than stormwater may not require a CDPS Industrial Wastewater Discharge permit and are considered Allowable Non Stormwater Discharges. Any of these discharge that exist at the site must be identified in the SWMP. See Part I. D. 4. b of the permit for the list of such allowable discharges. Part I Page No. 13 Permit No. COS 000008 C. STORMWATER MANAGEMENT PLAN  CONTENTS AND REQUIREMENTS 4. Comprehensive Inspections The SWMP shall identify qualified personnel that shall inspect designated equipment and plant areas. The procedures and intervals of the comprehensive inspection shall also be specified in the plan and shall be consistent with Part I. D. 6. Comprehensive inspections shall in no case be completed less than twice a year ( in the spring and fall). The operator shall keep a record of such inspections. This record shall be made available to the Division upon request and summarized in the Annual Report.

5. Consistency with Other Plans SWMPs may reflect requirements for Spill Prevention Control and Countermeasure ( SPCC) plans under section 311 of the CWA, or Best Management Practices ( BMPs) Programs otherwise required by a CDPS permit, and may incorporate any part of such plans into the SWMP by reference.

D. BASIC TERMS AND CONDITIONS 1. General Limitations The following limitations shall apply to all discharges authorized by this permit:

a. Bulk storage structures for petroleum products and other chemicals shall have adequate protection so as to contain all spills and prevent any spilled material from entering State waters.

b. No chemicals are to be added to the discharge unless permission for the use of a specific chemical is granted by the Division. In granting the use of such chemicals, special conditions and monitoring may be addressed by separate letter.

c. All dischargers must comply with the lawful requirements of counties, drainage districts and other state or local agencies regarding any discharges of stormwater to storm drain systems or other water courses under their jurisdiction.

d. Discharge of stormwater shall not cause continuing or recurring impairment of beneficial uses, or exceedances of water quality standards in receiving waters. Timely and complete implementation of the SWMP shall constitute compliance with receiving water standards. If receiving water standards violations occur that are determined to be attributable to DIA activities covered under this permit, DIA must evaluate their SWMP and determine what, if any, additional measures may be necessary to address the water quality concerns, and if necessary, implement additional or more effective BMPs, and submit to the Division revisions of the SWMP that will increase the likelihood of preventing future exceedances of water quality standards.

2. Best Management Practices ( BMPs)

Any BMPs included in DIA's SWMP become permit requirements, and must be carried out in order to remain in compliance with the permit. The SWMP modification process is outlined in Part I. D. 3 of the permit.

The following BMPs are listed in the permit as well as the SWMP. They cannot be changed without a permit amendment or modification, as opposed to only a SWMP modification. The BMPs listed in the permit are intended as general guidelines regarding deicing and operation of the spent ADF management system.

a. Full deicing activities are normally restricted to the areas at the site indicated in Figure 2. ( Figure 2 shows only those areas where deicing is allowed as of the issuance date of this permit. Future modifications to deicing areas during the permit term will not necessarily result in a change to Figure 2, but rather must be reflected in DIA's SWMP.) Under special situations, for safety reasons Airport Operations may grant permission for full deicing at the A and C concourse gates where it is not normally allowed. Full deicing at A and C concourse gates will only be allowed when authorized by the airport manager or his designee. Full deicing at any other areas is prohibited.

AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part I Page No. 14 Permit No. COS 000008 D. BASIC TERMS AND CONDITIONS b. To the maximum extent practicable, ADF mixed with stormwater runoff collected from the three west deicing pads is recycled at the on site recycling facilities. However, if the concentration of spent deicing fluid received by the facility is too low for recycling ( due to technical or economic factors), the fluid will instead be pumped to the Metro Wastewater Reclamation District ( Metro) for disposal.

c. The overall objective in operation of the spent ADF management system is to capture ADF after it has been applied. DIA's SWMP must contain BMPs specific to how influent valves will be positioned to capture spent ADF, how the system will be operated if storage volumes are nearing capacity, and how releases from a pond would occur.

d. DIA's contribution permit with Metro requires that records be maintained regarding pond levels and volumes. DIA shall also maintain records regarding influent valve positions, diversions, and releases from ponds to the clean stormwater system. Diversions and pond releases shall be summarized in the annual report.

AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part I Page No. 15 Permit No. COS 000008 D. BASIC TERMS AND CONDITIONS 3. Additional SWMP Requirements a. SWMP: The SWMP shall be updated as appropriate. A revised SWMP will be submitted in final form within 90 days after the effective date of this permit, to take into account any new requirements imposed by the permit.

b. SWMP Retention: A current copy of the SWMP shall be retained on site.

AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part I Page No. 16 Permit No. COS 000008 D. BASIC TERMS AND CONDITIONS c. SWMP Review/ Changes: Upon review of the SWMP, the Division may notify the permittee at any time that the plan does not meet one or more of the minimum requirements of this permit. After such notification, the permittee shall make changes to the plan and shall submit to the Division an update to the plan including the requested changes. Unless otherwise provided by the Division, the permittee shall have 30 days after such notification to both make the necessary changes to the plan and to implement them.

The permittee shall amend the plan whenever there is a change in design, construction, operation, or maintenance which has a significant effect on the potential for the discharge of pollutants to the waters of the State, or if the SWMP proves to be ineffective in achieving the general objectives of controlling pollutants in stormwater discharges associated with industrial activity. Amendments to the plan should be submitted to the Division with the following Annual Report. The Division reserves the right to require additional measures to prevent and control pollution, as needed.

4. Prohibition of Non stormwater Discharges a. Except as provided in section b, below, all discharges authorized by this permit shall be composed entirely of stormwater associated with industrial activity. Discharges which fall under the Division's regulations, and which are not authorized under this permit and consist of material other than stormwater associated with industrial activity, must be addressed in a separate CDPS permit issued for that discharge.

b. Discharges from the following sources that are combined with stormwater discharges associated with industrial activity may be authorized by this permit, provided that the non stormwater component of the discharge is identified in the SWMP ( see Part I. C. 3. h of the permit): fire fighting activities, uncontaminated compressor condensate, irrigation drainage, lawn watering, air conditioner condensate, uncontaminated springs, and foundation or footing drain where flows are not contaminated.

Stormwater discharges associated with deicing/ anti icing activities are authorized under this permit, as per the provisions in Part I. A. 1 of the permit. It should be noted, however, that deicing and anti icing of ground vehicle road and parking surfaces outside the Airport Operations Area are not regulated activities under this permit at this time.

5. Releases in Excess of Reportable Quantities This permit does not relieve the permittee of the reporting requirements of 40 C. F. R. 110, 40 C. F. R. 117 or 40 C. F. R. 302. Any discharge of hazardous substances must be handled in accordance with the Division's Notification Requirements ( see Parts II. A. 4 and II. A. 5 of the permit).

6. Facility Inspections Qualified personnel identified by the operator shall make a comprehensive inspection of their stormwater management system, at least twice per year ( in the spring and fall). These comprehensive inspections must be documented and summarized in the Annual Report ( see Part I. F. 1 of the permit).

a. Material handling areas, disturbed areas, areas used for material storage that are exposed to precipitation, and other potential sources of pollution identified in the SWMP in accordance with Part I. C. 3. b of this permit shall be inspected for evidence of, or the potential for, pollutants entering the drainage system. Structural stormwater management measures, sediment and control measures, and other structural pollution prevention measures identified in the plan shall be observed to ensure that they are operating correctly. A visual inspection of equipment needed to implement the plan, such as spill response equipment, shall be made.

b. Based on the results of the inspection, the description of potential pollutant sources and pollution prevention measures identified in the plan shall be revised as appropriate within two weeks of such inspection. Such revisions shall provide for implementation of any changes to the plan in a timely manner, but in no case more than 90 days after the inspection. Part I Page No. 17 Permit No. COS 000008 D. BASIC TERMS AND CONDITIONS c. A report summarizing the scope of the inspection, personnel making the inspection, the date( s) of the inspection, major observations relating to the implementation of the SWMP, and actions taken in accordance with paragraph ( b), above, shall be made and retained as part of the SWMP for at least three years. The report shall be signed in accordance with Part I. F. 6 of this permit.

7. SWMP Availability A copy of the SWMP shall be provided to EPA upon request, and within the time frame specified in the request. All SWMPs required under this permit are considered reports that shall be available to the public under Section 308( b) of the CWA. The owner or operator of a facility with stormwater discharges covered by this permit shall make plans available to members of the public upon request. However, the permittee may claim any portion of a stormwater pollution plan as confidential in accordance with 40 C. F. R. Part 2.

E. DEFINITIONS OF TERMS 1. " Daily Maximum limitation" means the limitation for this parameter shall be applied as an instantaneous maximum ( or, for pH or DO, instantaneous minimum) value. The instantaneous value is defined as the analytical result of any individual sample. DMRs shall include the maximum ( and/ or minimum) of all instantaneous values within the calendar month. Any instantaneous value beyond the noted daily maximum limitation for the indicated parameter shall be considered a violation of this permit.

2. " Grab" sample, is a single " dip and take" sample so as to be representative of the parameter being monitored.

3. " In situ" measurement is defined as a single reading, observation or measurement taken in the field at the point of discharge.

4. " Instantaneous" measurement is a single reading, observation, or measurement performed on site using existing monitoring facilities.

5. " Quarterly measurement frequency" means samples may be collected at any time during the calendar quarter ( e. g., January through March) if a continual discharge occurs. If the discharge is intermittent, then samples shall be collected during the period that discharge occurs.

6. " Twice Monthly ( 2X/ Month)" monitoring frequency means that two samples shall be collected each calendar month on separate weeks with at least one full week between the two sample dates. Also, there shall be at least one full week between the second sample of a month and the first sample of the following month.

7. " Visual" observation is observing the discharge to check for the presence of a visible sheen or floating oil.

8. " Water Quality Control Division" or " Division" means the state Water Quality Control Division as established in 25 8 101 et al.

Additional relevant definitions are found in the Colorado Water Quality Control Act, CRS

25 8 101 et seq., the Colorado Discharge Permit System Regulations, Regulation 61 ( 5 C. C. R. 1002 61) and other applicable regulations.

F. REPORTING REQUIREMENTS 1. Annual Report The permittee will be required to submit an Annual Report, covering October 1 through September 30 of each year ( except as noted under 1. e., below), on the overall compliance with the SWMP. The Annual Report shall contain, at a minimum: a. Name of permittee, address, phone number, and permit certification number. b. A report on the facility's overall compliance with the SWMP.

AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part I Page No. 18 Permit No. COS 000008 F. REPORTING REQUIREMENTS c. Changes made in the individual items of the SWMP, and any proposed changes. d. A summary of each comprehensive stormwater facility inspection made, including date, findings, and action taken. e. A summary of operations and capture efficiency achieved by the spent ADF management system will be provided by deicing season, and may cover a period different than that specified. Information to be reported includes total amounts of ADF that are: applied, recovered, treated ( via Metro), recycled, and not collected ( i. e., fugitive ADF). f. The report shall be signed and certified for accuracy by the permittee, including the certification language outlined in Part I. F. 6 of the permit.

The Annual Report will be due to the Division on or before November 28 of each year ( see address below). The Division reserves the right to require additional information in the report, on a case by case basis, as needed.

A signed copy of the above report form( s) shall be submitted to the following address:

Colorado Department of Public Health & Environment Water Quality Control Division WQCD P B2 4300 Cherry Creek Drive South Denver, Colorado 80246 1530 2. Additional Reporting DIA must submit a monthly status report on the status of glycol management at DIA, at least until the compliance schedule items have been completed. After that time, the monthly status report shall be required until such time as the Division determines that the increased reporting frequency is not necessary, based on DIA's compliance history. The monthly report shall be due by the 10th day of the following month.

3. Reporting to Municipality Any permitted facility discharging to a municipal storm sewer shall provide the municipality with a copy of the permit application, Annual Reports, and/ or Discharge Monitoring Reports, upon request. A copy of the SWMP shall also be provided to the municipality upon request.

4. Routine Reporting of Data Reporting of the data gathered in compliance with Part I. B. 1 shall be on a quarterly basis. Reporting of all data gathered shall comply with the requirements of Parts I. B and I. F. Monitoring results shall be summarized for each quarter and reported on Division approved discharge monitoring report ( DMR) forms. One form shall be mailed to the Water Quality Control Division, as indicated below, so that the DMR is received no later than the 28th day of the following month. If no discharge occurs during the reporting period, " No Discharge" shall be reported.

The first original signed copy of each discharge monitoring report ( DMR) shall be submitted to the Division at the following address:

Colorado Department of Public Health and Environment Water Quality Control Division WQCD P B2 4300 Cherry Creek Drive South Denver, Colorado 80246 1530 The Discharge Monitoring Report forms shall be filled out accurately and completely in accordance with requirements of this permit and the instructions on the forms. They shall be signed by an authorized person as identified in Part I. F. 6. Calculations for all limitations which require the averaging of measurements shall utilize an arithmetic mean unless otherwise specified by the Division in the permit.

AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part I Page No. 19 Permit No. COS 000008 F. REPORTING REQUIREMENTS If the permittee, using the approved analytical methods, monitors any parameter more frequently than required by this permit, then the results of such monitoring shall be included in the calculation and reporting of the values required in the Discharge Monitoring Report Form ( DMRs) or other forms as required by the Division. Such increased frequency shall also be indicated.

5. Records The permittee shall establish and maintain records. Those records shall include the following:

a. The date, type, exact location, and time of sampling or measurements; b. The individual( s) who performed the sampling or measurements; c. The date( s) the analyses were performed; d. The individual( s) who performed the analyses; e. The analytical techniques or methods used; f. The results of such analyses; and g. Any other observations which may result in an impact on the quality or quantity of the discharge as indicated in 40 C. F. R. 122.44 ( I)( 1)( iii).

The permittee shall retain for a minimum of three ( 3) years records of all monitoring information, including all original strip chart recordings for continuous monitoring instrumentation, all calibration and maintenance records, copies of all reports required by this permit and records of all data used to complete the application for this permit. This period of retention shall be extended during the course of any unresolved litigation regarding the discharge of pollutants by the permittee or when requested by the Division or EPA.

6. Signatory and Certification Requirements a. All reports and other information required by the Division, shall be signed and certified for accuracy by the permittee in accord with the following criteria:

1) In the case of corporations, by a principal executive officer of at least the level of vice president or his or her duly authorized representative, if such representative is responsible for the overall operation of the facility from which the discharge described in the form originates;

2) In the case of a partnership, by a general partner;

3) In the case of a sole proprietorship, by the proprietor;

4) In the case of a municipal, state, or other public facility, by either a principal executive officer, ranking elected official, or other duly authorized employee.

b. All reports required by permits, and other information requested by the Division shall be signed by a person as described above or by a duly authorized representative of that person. A person is a duly authorized representative only if:

1) The authorization is made in writing by a person described above;

2) The authorization specifies either an individual or a position having responsibility for the overall operation of the regulated facility or activity such as the position of plant manager, operator of a well or a well field, superintendent, position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters for the company. ( A duly authorized representative may thus be either a named individual or any individual occupying a named position); and,

3) The written authorization is submitted to the Division. Part I Page No. 20 Permit No. COS 000008 F. REPORTING REQUIREMENTS If an authorization as described in this section is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new authorization satisfying the requirements of this section must be submitted to the Division prior to or together with any reports, information, or applications to be signed by an authorized representative.

The permittee, or the duly authorized representative shall make and sign the following certification on all such documents:

" I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is to the best of my knowledge and belief, true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations." Part I Page No. 21 Permit No. COS 000008 G. FIGURES FIGURE 1 Part I Page No. 22 Permit No. COS 000008 FIGURE 2 AUTHORIZED AIRCRAFT DEICING AREAS AT DIA AND DEICING WASTE DETENTION PONDS/ STORAGE TANKS Part I Page No. 23 Permit No. COS 000008 FIGURE 3 STORMWATER MANAGEMENT FLOW SCHEMATIC Part I Page No. 24 Permit No. COS 000008 FIGURE 4 CONTAMINATED STORMWATER SYSTEM PROCESS SCHEMATIC Part I Page No. 25 Permit No. COS 000008 FIGURE 5  DIA SAMPLING SITES AMENDED: April 14, 2004 EFFECTIVE: May 14, 2004 Part II Page No. 26 Permit No.: COS 000008 PART II A. NOTIFICATION REQUIREMENTS 1. Notification to Parties All notification requirements under this section shall be directed as follows:

a. Oral notifications, other than for spills, during normal business hours shall be to:

Water Quality Protection Section  Industrial Compliance Water Quality Control Division Telephone: ( 303) 692 3500 Spills notifications at any time and other notifications after hours shall be to :

Emergency Management Unit Telephone: 1 877 518 5608 b. Written notification shall be to:

Water Quality Protection Section  Industrial Compliance Water Quality Control Division Colorado Department of Public Health and Environment WQCD WQP B2 4300 Cherry Creek Drive South Denver, CO 80246 1530 2. Change in Discharge The permittee shall notify the Division, in writing, of any planned physical alterations or additions to the permitted facility, or any significant changes in the type( s) of deicing or anti icing chemicals used. Notice is required only when:

a. The alteration or addition could significantly change the nature or increase the quantity or pollutants discharged; or b. The alteration or addition results in a significant change in the permittee's sludge use or disposal practices, and such alteration, addition, or change may justify the application of permit conditions that are different from or absent in the existing permit, including notification of additional use or disposal sites not reported pursuant to an approved land application plan.

The permittee shall give advance notice to the Division of any planned changes in the permitted facility or activity which may result in noncompliance with permit requirements.

Whenever notification of any planned physical alterations or additions to the permitted facility is required pursuant to this section, the permittee shall furnish the Division such plans and specifications which the Division deems reasonably necessary to evaluate the effect on the discharge, the stream, or ground water. If the Division finds that such new or altered discharge might be inconsistent with the conditions of the permit, the Division shall require a new or revised permit application and shall follow the procedures specified in Sections 61.5 through 61.6, and 61.15 of the Colorado Discharge Permit System Regulations.

3. Special Notifications  Definitions a. Bypass: The unpermitted intentional diversion of waste streams from any portion of a treatment facility.

b. Severe Property Damage: Substantial physical damage to property at the treatment facilities which causes them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. It does not mean economic loss caused by delays in production. A. NOTIFICATION REQUIREMENTS c. Spill: An incident in which flows or solid materials are accidentally or unintentionally allowed to flow or escape so as to be Part II Page No. 27 Permit No.: COS 000008 lost from the treatment, processing or manufacturing system which may cause or threaten pollution of state waters.

d. Upset: An exceptional incident in which there is unintentional and temporary noncompliance with permit effluent limitations because of factors beyond the reasonable control of the permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventative maintenance, or careless or improper operation.

4. Noncompliance Notification a. If, for any reason, the permittee does not comply with or will be unable to comply with any discharge limitations or standards specified in this permit, the permittee shall, at a minimum, provide the Division and EPA with the following information:

1) A description of the discharge and cause of noncompliance;

2) The period of noncompliance, including exact dates and times and/ or the anticipated time when the discharge will return to compliance; and 3) Steps being taken to reduce, eliminate, and prevent recurrence of the noncomplying discharge.

b. Unless otherwise specified in the permit, the permittee shall report the following circumstances orally within twenty four ( 24) hours from the time the permittee becomes aware of the circumstances, and shall mail to the Division a written report containing the information requested in Part II. A. 4 ( a) within five ( 5) days after becoming aware of the following circumstances:

1) Circumstances leading to any noncompliance which may endanger health or the environment regardless of the cause of the incident;

2) Circumstances leading to any unanticipated bypass which exceeds any effluent limitations in the permit;

3) Circumstances leading to any upset or spill which causes an exceedance of any effluent limitation in the permit;

4) Daily maximum violations for any of the pollutants limited by Part I. A of this permit and specified as requiring 24 hour notification. This includes any toxic pollutant or hazardous substance or any pollutant specifically identified as the method to control any toxic pollutant or hazardous substance.

c. The permittee shall report instances of non compliance which are not required to be reported within 24 hours at the time Discharge Monitoring Reports are submitted. The reports shall contain the information listed in sub paragraph ( a) of this section.

5. Other Notification Requirements Reports of compliance or noncompliance with, or any progress reports on, interim and final requirements contained in any compliance schedule in the permit shall be submitted no later than fourteen ( 14) days following each scheduled date, unless otherwise provided by the Division.

The permittee shall notify the Division, in writing, thirty ( 30) days in advance of a proposed transfer of permit as provided in Part II. B. 4.

The permittee's notification of all anticipated noncompliance does not stay any permit condition.

All existing manufacturing, commercial, mining, and silvicultural dischargers must notify the Division as soon as they know or have reason to believe: Part II Page No. 28 Permit No.: COS 000008 A. NOTIFICATION REQUIREMENTS a. That any activity has occurred or will occur which would result in the discharge, on a routine or frequent basis, of any toxic pollutant which is not limited in the permit, if that discharge will exceed the highest of the following " notification levels":

1) One hundred micrograms per liter ( 100 µ g/ l);

2) Two hundred micrograms per liter ( 200 µ g/ l) for acrolein and acrylonitrile; five hundred micrograms per liter ( 500 µ g/ l) for 2.4 dinitrophenol and 2 methyl 4.6 dinitrophenol; and one milligram per liter ( 1 mg/

) for antimony;

3) Five ( 5) times the maximum concentration value reported for that pollutant in the permit application in accordance with Section 61.4( 2)( g).

4) The level established by the Division in accordance with 40 C. F. R.

122.44( f).

b. That any activity has occurred or will occur which would result in any discharge, on a non routine or infrequent basis, of a toxic pollutant which is not limited in the permit, if that discharge will exceed the highest of the following " notification levels":

1) Five hundred micrograms per liter ( 500 µ g/ l);

2) One milligram per liter ( 1 mg/

) for antimony; and 3) Ten ( 10) times the maximum concentration value reported for that pollutant in the permit application.

4) The level established by the Division in accordance with 40 C. F. R.

122.44( f).

6. Bypass Notification If the permittee knows in advance of the need for a bypass, a notice shall be submitted, at least ten days before the date of the bypass, to the Division. The bypass shall be subject to Division approval and limitations imposed by the Division. Violations of requirements imposed by the Division will constitute a violation of this permit.

7. Upsets a. Effect of an Upset An upset constitutes an affirmative defense to an action brought for noncompliance with permit effluent limitations if the requirements of paragraph ( b) of this section are met. No determination made during administrative review of claims that noncompliance was caused by upset, and before an action for noncompliance, is final administrative action subject to judicial review.

b. Conditions Necessary for a Demonstration of Upset A permittee who wishes to establish the affirmative defense of upset shall demonstrate through properly signed contemporaneous operating logs, or other relevant evidence that:

1) An upset occurred and that the permittee can identify the specific cause( s) of the upset; and 2) The permitted facility was at the time being properly operated and maintained; and 3) The permittee submitted proper notice of the upset as required in Part II. A. 4. of this permit ( 24 hour notice); and Part II Page No. 29 Permit No.: COS 000008 A. NOTIFICATION REQUIREMENTS 4) The permittee complied with any remedial measure necessary to minimize or prevent any discharge or sludge use or disposal in violation of this permit which has a reasonable likelihood of adversely affecting human health or the environment.

In addition to the demonstration required above, a permittee who wishes to establish the affirmative defense of upset for a violation of effluent limitations based upon water quality standards shall also demonstrate through monitoring, modeling or other methods that the relevant standards were achieved in the receiving water.

c. Burden of Proof In any enforcement proceeding the permittee seeking to establish the occurrence of an upset has the burden of proof.

8. Discharge Point Any discharge to the waters of the State from a point source other than specifically authorized by this permit is prohibited.

9. Proper Operation and Maintenance The permittee shall at all times properly operate and maintain all facilities and systems of treatment and control ( and related appurtenances) which are installed or used by the permittee as necessary to achieve compliance with the conditions of this permit. Proper operation and maintenance includes effective performance and adequate laboratory and process controls, including appropriate quality assurance procedures. This provision requires the operation of back up or auxiliary facilities or similar systems which are installed by the permittee only when necessary to achieve compliance with the conditions of the permit.

10. Minimization of Adverse Impact The permittee shall take all reasonable steps to minimize or prevent any discharge of sludge use or disposal in violation of this permit which has a reasonable likelihood of adversely affecting human health or the environment. As necessary, accelerated or additional monitoring to determine the nature and impact of the noncomplying discharge is required.

11. Removed Substances Solids, sludges, or other pollutants removed in the course of treatment or control of wastewaters shall be disposed in accordance with applicable state and federal regulations.

For all domestic wastewater treatment works, at industrial facilities, the permittee shall dispose of sludge in accordance with all State and Federal regulations.

12. Submission of Incorrect or Incomplete Information Where the permittee failed to submit any relevant facts in a permit application, or submitted incorrect information in a permit application or report to the Division, the permittee shall promptly submit the relevant information which was not submitted or any additional information needed to correct any erroneous information previously submitted 13. Bypass a. Bypasses are prohibited and the Division may take enforcement action against the permittee for bypass, unless:

1) The bypass is unavoidable to prevent loss of life, personal injury, or severe property damage; Part II Page No. 30 Permit No.: COS 000008 A. NOTIFICATION REQUIREMENTS 2) There were no feasible alternatives to bypass such as the use of auxiliary treatment facilities, retention of untreated wastes, or maintenance during normal periods of equipment downtime. This condition is not satisfied if adequate back up equipment should have been installed in the exercise of reasonable engineering judgment to prevent a bypass which occurred during normal periods of equipment downtime or preventive maintenance; and 3) Proper notices were submitted in compliance with Part II. A. 4.

b. " Severe property damage" as used in this Subsection means substantial physical damage to the treatment facilities which causes them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass. Severe property damage does not mean economic loss caused by delays in production.

c. The permittee may allow a bypass to occur which does not cause effluent limitations to be exceeded, but only if it also is for essential maintenance or to assure optimal operation. These bypasses are not subject to the provisions of paragraph ( a) above.

d. The Division may approve an anticipated bypass, after considering adverse effects, if the Division determines that the bypass will meet the conditions specified in paragraph ( a) above.

14. Reduction, Loss, or Failure of Treatment Facility The permittee has the duty to halt or reduce any activity if necessary to maintain compliance with the effluent limitations of the permit. Upon reduction, loss, or failure of the treatment facility, the permittee shall, to the extent necessary to maintain compliance with its permit, control production, control sources of wastewater, or all discharges, until the facility is restored or an alternative method of treatment is provided. This provision also applies to power failures, unless an alternative power source sufficient to operate the wastewater control facilities is provided.

It shall not be a defense for a permittee in an enforcement action that it would be necessary to halt or reduce the permitted activity in order to maintain compliance with the conditions of this permit.

B. RESPONSIBILITIES 1. Inspections and Right to Entry The permittee shall allow the Division and/ or the authorized representative, upon the presentation of credentials:

a. To enter upon the permittee's premises where a regulated facility or activity is located or in which any records are required to be kept under the terms and conditions of this permit;

b. At reasonable times to have access to and copy any records required to be kept under the terms and conditions of this permit and to inspect any monitoring equipment or monitoring method required in the permit; and c. To enter upon the permittee's premises in a reasonable manner and at a reasonable time to inspect and/ or investigate, any actual, suspected, or potential source of water pollution, or to ascertain compliance or non compliance with the Colorado Water Quality Control Act or any other applicable state or federal statute or regulation or any order promulgated by the Division. The investigation may include, but is not limited to, the following: sampling of any discharge and/ or process waters, the taking of photographs, interviewing of any person having knowledge related to the discharge permit or alleged violation, access to any and all facilities or areas within the permittee's premises that may have any affect on the discharge, permit, or alleged violation. Such entry is also authorized for the purpose of inspecting and copying records required to be kept concerning any effluent source.

d. The permittee shall provide access to the Division to sample the discharge at a point after the final treatment process but prior to the discharge mixing with state waters upon presentation of proper credentials.

B. RESPONSIBILITIES In the making of such inspections, investigations, and determinations, the Division, insofar as practicable, may designate as its Part II Page No. 31 Permit No.: COS 000008 authorized representatives any qualified personnel of the Department of Agriculture. The Division may also request assistance from any other state or local agency or institution.

2. Duty to Provide Information The permittee shall furnish to the Division, within a reasonable time, any information which the Division may request to determine whether cause exists for modifying, revoking and reissuing, or terminating this permit, or to determine compliance with this permit. The permittee shall also furnish to the Division, upon request, copies of records required to be kept by this permit.

3. Transfer of Ownership or Control a. Except as provided in paragraph b. of this section, a permit may be transferred by a permittee only if the permit has been modified or revoked and reissued as provided in Section 61.8( 8) of the Colorado Discharge Permit System Regulations, to identify the new permittee and to incorporate such other requirements as may be necessary under the Federal Act.

b. A permit may be automatically transferred to a new permittee if:

1) The current permittee notifies the Division in writing 30 days in advance of the proposed transfer date; and 2) The notice includes a written agreement between the existing and new permittee( s) containing a specific date for transfer of permit responsibility, coverage and liability between them; and 3) The Division does not notify the existing permittee and the proposed new permittee of its intent to modify, or revoke and reissue the permit.

4) Fee requirements of the Colorado Discharge Permit System Regulations, Section 61.15, have been met.

4. Availability of Reports Except for data determined to be confidential under Section 308 of the Federal Clean Water Act and the Colorado Discharge Permit System Regulations 5 C. C. R. 1002 61, Section 61.5( 4), all reports prepared in accordance with the terms of this permit shall be available for public inspection at the offices of the Division and the Environmental Protection Agency.

The name and address of the permit applicant( s) and permittee( s), permit applications, permits and effluent data shall not be considered confidential. Knowingly making false statement on any such report may result in the imposition of criminal penalties as provided for in Section 309 of the Federal Clean Water Act, and Section 25 8 610 C. R. S.

5. Modification, Suspension, Revocation, or Termination of Permits By the Division The filing of a request by the permittee for a permit modification, revocation and reissuance, termination or a notification of planned changes or anticipated noncompliance, does not stay any permit condition.

a. A permit may be modified, suspended, or terminated in whole or in part during its term for reasons determined by the Division including, but not limited to, the following:

1) Violation of any terms or conditions of the permit;

2) Obtaining a permit by misrepresentation or failing to disclose any fact which is material to the granting or denial of a permit or to the establishment of terms or conditions of the permit; or 3) Materially false or inaccurate statements or information in the permit application or the permit. Part II Page No. 32 Permit No.: COS 000008 B. RESPONSIBILITIES 4) A determination that the permitted activity endangers human health or the classified or existing uses of state waters and can only be regulated to acceptable levels by permit modifications or termination.

b. A permit may be modified in whole or in part for the following causes, provided that such modification complies with the provisions of Section 61.10 of the Colorado Discharge Permit System Regulations:

1) There are material and substantial alterations or additions to the permitted facility or activity which occurred after permit issuance which justify the application of permit conditions that are different or absent in the existing permit.

2) The Division has received new information which was not available at the time of permit issuance ( other than revised regulations, guidance, or test methods) and which would have justified the application of different permit conditions at the time of issuance. For permits issued to new sources or new dischargers, this cause includes information derived from effluent testing required under Section 61.4( 7)( e) of the Colorado Discharge Permit System Regulations. This provision allows a modification of the permit to include conditions that are less stringent than the existing permit only to the extent allowed under Section 61.10 of the Colorado Discharge Permit System Regulations.

3) The standards or regulations on which the permit was based have been changed by promulgation of amended standards or regulations or by judicial decision after the permit was issued. Permits may be modified during their terms for this cause only as follows:

a) The permit condition requested to be modified was based on a promulgated effluent limitation guideline, EPA approved water quality standard, or an effluent limitation set forth in 5 C. C. R. 1002 62,

62 et seq.; and b) EPA has revised, withdrawn, or modified that portion of the regulation or effluent limitation guideline on which the permit condition was based, or has approved a Commission action with respect to the water quality standard or effluent limitation on which the permit condition was based; and c) The permittee requests modification after the notice of final action by which the EPA effluent limitation guideline, water quality standard, or effluent limitation is revised, withdrawn, or modified; or d) For judicial decisions, a court of competent jurisdiction has remanded and stayed EPA promulgated regulations or effluent limitation guidelines, if the remand and stay concern that portion of the regulations or guidelines on which the permit condition was based and a request is filed by the permittee in accordance with this Regulation, within ninety ( 90) days of judicial remand.

4) The Division determines that good cause exists to modify a permit condition because of events over which the permittee has no control and for which there is no reasonable available remedy.

5) The permittee has received a variance.

6) When required to incorporate applicable toxic effluent limitation or standards adopted pursuant to Section 307( a) of the Federal Act.

7) When required by the reopener conditions in the permit.

8) As necessary under 40 C. F. R. 403.8( e), to include a compliance schedule for the development of a pretreatment program.

9) When the level of discharge of any pollutant which is not limited in the permit exceeds the level which can be achieved by the technology based treatment requirements appropriate to the permittee under Section 61.8( 2) of the Colorado Discharge Permit System Regulations.

10) To establish a pollutant notification level required in Section 61.8( 5) of the Colorado Discharge Permit System Regulations. Part II Page No. 33 Permit No.: COS 000008 B. RESPONSIBILITIES 11) To correct technical mistakes, such as errors in calculation, or mistaken interpretations of law made in determining permit conditions, to the extent allowed in Section 61.10 of the Colorado State Discharge Permit System Regulations.

12) When required by a permit condition to incorporate a land application plan for beneficial reuse of sewage sludge, to revise an existing land application plan, or to add a land application plan.

13) For any other cause provided in Section 61.10 of the Colorado Discharge Permit System Regulations.

c. At the request of a permittee, the Division may modify or terminate a permit and issue a new permit if the following conditions are met:

1) The Regional Administrator has been notified of the proposed modification or termination and does not object in writing within thirty ( 30) days of receipt of notification,

2) The Division finds that the permittee has shown reasonable grounds consistent with the Federal and State statutes and regulations for such modifications or termination;

3) Requirements of Section 61.15 of the Colorado Discharge Permit System Regulations have been met, and 4) Requirements of public notice have been met.

d. Permit modification ( except for minor modifications), termination or revocation and reissuance actions shall be subject to the requirements of Sections 61.5( 2), 61.5( 3), 61.6, 61.7 and 61.15 of the Colorado Discharge Permit System Regulations. The Division shall act on a permit modification request, other than minor modifications requests, within 180 days of receipt thereof. Except for minor modifications, the terms of the existing permit govern and are enforceable until the newly issued permit is formally modified or revoked and reissued following public notice.

e. Upon consent by the permittee, the Division may make minor permit modifications without following the requirements of Sections 61.5( 2), 61.5( 3), 61.7, and 61.15 of the Colorado Discharge Permit System Regulations. Minor modifications to permits are limited to:

1) Correcting typographical errors; or 2) Increasing the frequency of monitoring or reporting by the permittee; or 3) Changing an interim date in a schedule of compliance, provided the new date of compliance is not more than 120 days after the date specific in the existing permit and does not interfere with attainment of the final compliance date requirement; or 4) Allowing for a transfer in ownership or operational control of a facility where the Division determines that no other change in the permit is necessary, provided that a written agreement containing a specific date for transfer of permit responsibility, coverage and liability between the current and new permittees has been submitted to the Division; or 5) Changing the construction schedule for a discharger which is a new source, but no such change shall affect a discharger's obligation to have all pollution control equipment installed and in operation prior to discharge; or 6) Deleting a point source outfall when the discharge from that outfall is terminated and does not result in discharge of pollutants from other outfalls except in accordance with permit limits.

f. When a permit is modified, only the conditions subject to modification are reopened. If a permit is revoked and reissued, the entire permit is reopened and subject to revision and the permit is reissued for a new term.

g. The filing of a request by the permittee for a permit modification, revocation and reissuance or termination does not stay any permit condition. Part II Page No. 34 Permit No.: COS 000008 B. RESPONSIBILITIES h. All permit modifications and reissuances are subject to the antibacksliding provisions set forth in 61.10( e) through ( g).

6. Oil and Hazardous Substance Liability Nothing in this permit shall be construed to preclude the institution of any legal action or relieve the permittee from any responsibilities, liabilities, or penalties to which the permittee is or may be subject to under Section 311 ( Oil and Hazardous Substance Liability) of the Clean Water Act.

7. State Laws Nothing in this permit shall be construed to preclude the institution of any legal action or relieve the permittee from any responsibilities, liabilities, or penalties established pursuant to any applicable State law or regulation under authority granted by Section 510 of the Clean Water Act.

8. Permit Violations Failure to comply with any terms and/ or conditions of this permit shall be a violation of this permit. The discharge of any pollutant identified in this permit more frequently than or at a level in excess of that authorized shall constitute a violation of the permit.

9. Property Rights The issuance of this permit does not convey any property or water rights in either real or personal property, or stream flows, or any exclusive privileges, nor does it authorize any injury to private property or any invasion of personal rights, nor any infringement of Federal, State or local laws or regulations.

10. Severability The provisions of this permit are severable. If any provisions of this permit, or the application of any provision of this permit to any circumstance, is held invalid, the application of such provision to other circumstances and the application of the remainder of this permit shall not be affected.

11. Renewal Application If the permittee desires to continue to discharge, a permit renewal application shall be submitted at least one hundred eighty ( 180) days before this permit expires. If the permittee anticipates there will be no discharge after the expiration date of this permit, the Division should be promptly notified so that it can terminate the permit in accordance with Part II. B. 5.

12. Confidentiality Any information relating to any secret process, method of manufacture or production, or sales or marketing data which has been declared confidential by the permittee, and which may be acquired, ascertained, or discovered, whether in any sampling investigation, emergency investigation, or otherwise, shall not be publicly disclosed by any member, officer, or employee of the Commission or the Division, but shall be kept confidential. Any person seeking to invoke the protection of this Subsection ( 12) shall bear the burden of proving its applicability. This section shall never be interpreted as preventing full disclosure of effluent data.

13. Fees The permittee is required to submit payment of an annual fee as set forth in the 1983 amendments to the Water Quality Control Act. Section 25 8 502 ( l) ( b), and the Colorado Discharge Permit System Regulations 5 C. C. R. 1002 61, Section 61.15 as amended. Failure to submit the required fee when due and payable is a violation of the permit and will result in enforcement action pursuant to Section 25 8 601 et. seq., C. R. S. 1973 as amended. Part II Page No. 35 Permit No.: COS 000008 B. RESPONSIBILITIES 14. Duration of Permit The duration of a permit shall be for a fixed term and shall not exceed five ( 5) years. Filing of a timely and complete application shall cause the expired permit to continue in force to the effective date of the new permit. The permit's duration may be extended only through administrative extensions and not through interim modifications.

15. Section 307 Toxics If a toxic effluent standard or prohibition, including any applicable schedule of compliance specified, is established by regulation pursuant to Section 307 of the Federal Act for a toxic pollutant which is present in the permittee's discharge and such standard or prohibition is more stringent than any limitation upon such pollutant in the discharge permit, the Division shall institute proceedings to modify or revoke and reissue the permit to conform to the toxic effluent standard or prohibition.

16. Antibacksliding a. A permit may not be renewed, reissued, or modified to contain effluent limitations adopted pursuant to Section 25 8 503( 1)( b) ( BPJ) of the Water Quality Control Act, which are less stringent than the comparable effluent limitations or standards in the previous permit, unless any one of the following exceptions is met and the conditions of paragraph ( c) of this section are met:

1) Material and substantial alterations or additions to the permitted facility occurred after permit issuance which justify the application of less stringent effluent limitations; or 2) Information is available which was not available at the time of permit issuance ( other than revised regulations, guidance, or test methods) and which would have justified the application of a less stringent effluent limitation or standard at the time of permit issuance; or 3) The Division determines that technical mistakes or mistaken interpretations of law were made in issuing the permit, which justified relaxation of the effluent limitations or standards; or 4) A less stringent effluent limitation or standard is necessary because of events over which the permittee has no control and for which there is not reasonable available remedy; or 5) The permittee has received a permit variance; or 6) The permittee has installed the treatment facilities required to meet the effluent limitations in the previous permit and has properly operated and maintained the facilities but has nevertheless been unable to achieve the previous effluent limitations, in which case, the limitations in the renewed, reissued, or modified permit may reflect the level of pollutant control actually achieved ( but shall not be less stringent than required by effluent guidelines in effect at the time of permit renewal, reissuance, or modification).

b. A permit may not be renewed, reissued, or modified to contain effluent limitations adopted pursuant to 61.8( 2( b) or ( c) of the Colorado Discharge Permit System Regulations that are less stringent than the comparable effluent limitations in the previous permit, unless any of the exceptions provided herein is met and the conditions of paragraph c. of this section are met.

1) In waters where the applicable water quality standard has not yet been attained, effluent limitations based on a total maximum daily load or other waste load allocation may be revised to be less stringent if the cumulative effect of all such revisions assures attainment of such water quality standard, or the designated use which is not being attained is removed in accordance with Section 31.6 of the Basic Standards. Part II Page No. 36 Permit No.: COS 000008 B. RESPONSIBILITIES 2) In waters where the applicable water quality standard has been attained, effluent limitations based on a total maximum daily load, other waste load allocation, or any other permitting standard ( including any water quality standard) may be revised to be less stringent if such revision is subject to and consistent with the antidegradation provisions of Section 31.8 of the Basic Standards. Consistency with Section 31.8 shall be presumed if the waters in question have been designated by the Commission as " use protected"; or 3) Whether or not the applicable water quality standard has been attained:

a) Material and substantial alterations or additions to the permitted facility occurred after permit issuance which justified the application of less stringent effluent limitations; or b) A less stringent effluent limitation is necessary because of events over which the permittee has no control and for which there is not reasonable available remedy; or c) The permittee has received a permit variance; or d) The permittee has installed the treatment facilities required to meet the effluent limitations in the previous permit and has properly operated and maintained the facilities but has nevertheless been unable to achieve the previous effluent limitations, in which case, the limitations in the reviewed, reissued, or modified permit may reflect the level of pollutant control actually achieved ( but shall not be less stringent than required by effluent guidelines in effect at the time of permit renewal, reissuance, or modification).

c. In no event may a permit with respect to which paragraphs ( a) and ( b) of this section apply be renewed, reissued, or modified to contain an effluent limitation or standard which is less stringent than required by federal effluent guidelines in effect at the time the permit is renewed, reissued, or modified. In no event may such a permit to discharge into state waters be renewed, reissued, or modified to contain a less stringent effluent limitation if the implementation of such limitation would result in a violation of an applicable water quality standard.

17. Effect of Permit Issuance a. The issuance of a permit does not convey any property rights or any exclusive privilege.

b. The issuance of a permit does not authorize any injury to person or property or any invasion of personal rights, nor does it authorize the infringement of federal, state, or local laws or regulations.

c. Except for any toxic effluent standard or prohibition imposed under Section 307 of the Federal act or any standard for sewage sludge use or disposal under Section 405( d) of the Federal act, compliance with a permit during its term constitutes compliance, for purposes of enforcement, with Sections 301, 302, 306, 318, 403, and 405( a) and ( b) of the Federal act. However, a permit may be modified, revoked and reissued, or terminated during its term for cause as set forth in Section 61.8( 8) of the Colorado Discharge Permit System Regulations.