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Background

The Office of Wastewater Management of the U.S. Environmental Protection Agency’s (EPA’s) Office of Water prepared this guidance document to assist municipalities that own or operate publicly owned treatment works (POTWs) in developing and implementing local pretreatment programs.

Section 402(b) of the Clean Water Act (CWA) provides for EPA to authorize a State to administer its own National Pollutant Discharge Elimination System (NPDES) permit program. In order to be authorized, a State program must include adequate authority to issue permits that ensure compliance with the CWA including section 307(b) pretreatment standards. The program must ensure that permits issued to POTWs include a program to assure compliance with pretreatment standards by significant sources introducing pollutants subject to such standards to the POTW. [Section 402(b)(8), 33 U.S.C. § 1342(b)(8)]. This guidance will assist POTWs in their efforts to meet their requirement to develop pretreatment programs.

Disclaimer

The discussion in this document is intended solely as guidance. This guidance is not a regulation nor does not it substitute for any requirements under the CWA or EPA’s regulations.

Thus, it does not impose legally binding requirements on EPA, States, municipalities or the regulated community. The general descriptions provided in this document may not apply to a particular situation based upon the circumstances. This guidance does not confer legal rights or impose legal obligations upon any member of the public.

Among other things, the document describes existing requirements with respect to industrial dischargers and POTWs under the CWA and its implementing regulations at 40 CFR 122, 123, 124, and 403 and chapter I, subchapter N. While EPA has made every effort to ensure the accuracy of the discussion in this guidance, a discharger’s obligations are determined, in the case of directly discharging POTWs, by the terms of their NPDES permit and EPA’s regulations or, in the case of indirect dischargers, by permits or equivalent control mechanisms issued to POTW industrial users or by regulatory requirements. Nothing in this guidance changes any statutory or regulatory requirement. In the event of a conflict between the discussion in this guidance and any permit or regulation, the permit or regulation would be controlling. EPA and local decision makers retain the discretion to adopt approaches on a case-by-case basis that differ from those described in this guidance where appropriate and authorized by EPA regulations, State law, or local ordinances.

Mention of trade names or commercial products does not constitute endorsement or recommendation for their use.

EPA may decide to revise this guidance without public notice to reflect changes in the Agency’s approach to implementing pretreatment standards or to clarify and update text. To determine whether the Agency has revised this guidance and/or to obtain copies, contact the Water Permits Division at

(202) 564-9545. You can also determine whether EPA has revised or supplemented the information in this guidance by accessing the document at: http://www.epa.gov/NPDES/pretreatment.

CONTENTS

Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv

Chapter 1 - Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 - 1

1.1 Purpose of This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 - 1

1.2 Local Limits Statutory Authority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 - 1

1.3 Local Limits Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 - 1

1.4 National Pretreatment Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 - 2

1.4.1 Prohibited Discharges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 - 2

1.4.2 Categorical Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 - 3

1.4.3 Local Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 - 3

1.5 The Relationship of Local Limits to Categorical Standards . . . . . . . . . . . . . . . . . . . . . . . 1 - 3

1.6 Organization of the Guidance Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 - 4

Chapter 2 - Overview of Local Limits Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 1

2.1 Local Limits Decision Tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 1

2.2 MAHL Approach to Local Limits Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 3

2.2.1 Step 1: Determine Pollutants of Concern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 4

2.2.2 Step 2: Collect and Analyze Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 4

2.2.3 Step 3: Calculate MAHLs for Each POC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 4

2.2.4 Step 4: Designate and Implement Local Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 4

2.2.5 Step 5: Addressing Collection System Concerns . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 4

Chapter 3 - Determining Pollutants of Concern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 -

3.1 National POCs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 1

3.2 Other Potential POCs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 -

3.2.1 NPDES Permit Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 2

3.2.2 Water Quality Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 -

3.2.3 Sludge Quality Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 4

3.2.4 Air Quality Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 -

3.2.5 Resource Protection Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 5

3.2.6 Prohibitions on Treatment Plant Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 -

3.2.7 Prohibitions to Protect the Treatment Works, Collection System, and Workers . . . 3 - 5

3.2.8 Scans of POTW Influent, Effluent, and Sludge to Identify Priority Pollutants . . . . 3 -

3.2.9 Evaluations of Industrial and Commercial Discharges . . . . . . . . . . . . . . . . . . . . . . 3 - 7

3.2.10 Hauled Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 8

3.2.11 Remediation Site Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 9

3.2.12 Hazardous Wastes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 11

3.3 Approval Authority Screening Process to Select Pollutants for Local Limits Sampling

Program and Limit Development . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 11

3.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 12

Chapter 4 - Data Needed to Develop Local Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 1

4.1 Sampling Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 2 v

4.1.1 At the POTW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 2

4.1.2 In the Collection System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 3

4.1.3 At Industrial Users . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 4

4.2 Pollutants for Which POTWs Should Sample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 4

4.3 Sampling Frequencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 5

4.3.1 Sampling Frequencies for Initial Program Development . . . . . . . . . . . . . . . . . . . . . 4 - 5

4.3.2 Sampling Frequencies for Ongoing Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 6

4.4 Other Sampling Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 7

4.5 Sampling Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 8

4.6 Analytical Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 10

4.7 Information Collection and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 13

4.8 Review and Evaluation of Analytical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 13

4.9 Flow Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 14

4.9.1 Total POTW Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 14

4.9.2 Sludge Flow to the Digester . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 14

4.9.3 Sludge Flow to Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 14

4.9.4 Flows from Controlled Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 15

4.9.5 Flows from Uncontrolled Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 16

4.10 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 16

Chapter 5 - Calculation of Maximum Allowable Headworks Loadings . . . . . . . . . . . . . . . . . . . . . . . . 5 - 1

5.1 Calculation of Removal Efficiencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 1

5.1.1 Removal Efficiency Calculation Methodologies . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 3

5.1.2 Guidance on Using Different Methodologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 5

5.1.3 Data Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 6

5.1.4 Applying Removal Efficiencies Reported by Others . . . . . . . . . . . . . . . . . . . . . . . . 5 - 7

5.2 Calculation of Allowable Headworks Loadings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 8

5.2.1 Determination of Suitable Environmental Criteria . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 8

5.2.2 Effluent-Quality Based AHLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 11

5.2.3 Sludge-Quality Based AHLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 14

5.2.4 Inhibition-Based AHLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 19

5.2.5 Air-Quality Based AHLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 21

5.3 AHLs for Conventional and Non-Conventional Pollutants . . . . . . . . . . . . . . . . . . . . . . . 5 - 21

5.3.1 BOD/TSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 22

5.3.2 Ammonia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 23

5.3.3 Oil and Grease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 23

5.4 Determination of the Maximum Allowable Headworks Loading . . . . . . . . . . . . . . . . . 5 - 25

5.5 Sample MAHL Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 25

5.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 26

Chapter 6 - Designating and Implementing Local Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 1

6.1 Determination of the Need for New Local Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 1

6.1.1 Actual Loadings vs. MAHL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 2

6.1.2 Noncompliance Due to Pass Through or Interference . . . . . . . . . . . . . . . . . . . . . . . 6 - 2

6.1.3 Establishing Local Limits for Conventional Pollutants . . . . . . . . . . . . . . . . . . . . . . 6 - 2

6.2 Calculation of Maximum Allowable Industrial Loading . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 4

6.2.1 Uncontrolled Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 5

6.2.2 Hauled Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 6

6.2.3 Safety Factor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 6

6.2.4 Expansion/Growth Allowance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 7 vi

6.3 Comparison of MAIL Allocation and Implementation Methods . . . . . . . . . . . . . . . . . . . 6 - 7

6.4 Allocation of MAILs Among Controlled Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 8

6.4.1 Limit Duration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 8

6.4.2 Allocation Approaches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 10

6.5 Common Sense Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 13

6.6 Best Management Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 14

6.7 Approval Authority and Adoption Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 15

6.8 Public Participation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 17

6.9 Control Mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 18

6.10 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 19

Chapter 7 - Local Limits Reviews and Detailed Re-Evaluations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 1

7.1 Reviews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 1

7.1.1 Comparison of Current Loadings with MAHLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 1

7.1.2 Review of Compliance History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 3

7.1.3 Next Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 3

7.2 Detailed Local Limits Re-Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 3

7.2.1 Step 1: Assess Current Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 4

7.2.2 Step 2: Collect and Analyze Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 5

7.2.3 Step 3: Recalculate Existing, or Determine New, MAHLs . . . . . . . . . . . . . . . . . . . 7 - 6

7.2.4 Step 4: Implement the Local Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 6

7.3 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 7

Chapter 8 - Local Limits to Address Concerns About Collection Systems . . . . . . . . . . . . . . . . . . . . . . 8 - 1

8.1 Fires and Explosions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 1

8.1.1 Flashpoint Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 1

8.1.2 Lower Explosive Limit Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 2

8.1.3 Sample Headspace Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 2

8.1.4 Flammability and Explosivity Discharge Screening Levels . . . . . . . . . . . . . . . . . . 8 - 3

8.2 Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 4

8.2.1 pH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 4

8.2.2 Corrosive Pollutants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 4

8.3 Flow Obstructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 5

8.4 Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 6

8.5 Toxic Gases, Vapors, and Fumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 7

8.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 - 8

Chapter 9 - Questions and Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 1

9.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 1

9.2 Potential Pollutants of Concern . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 3

9.3 Sampling and Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 3

9.4 Determining MAHLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 5

9.5 Establishing Local Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 7

9.6 Oversight and Public Participation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 12

9.7 Implementation and Enforcement of Local Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 13

9.8 POTW Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 14

9.9 Industrial Users . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 14 vii

List of Tables Table 1-1: Comparison of Categorical Pretreatment Standards and Local Limits . . . . . . . . . . . . . . . . 1 - 4

Table 3-1: Selected Information Sources for Determining Potential POCs . . . . . . . . . . . . . . . . . . . . . 3 - 8

Table 4-1: Minimum Recommended Sampling Days for Initial Local Limits Development . . . . . . . . 4 - 6

Table 4-2: Minimum Recommended Sampling Frequencies for Ongoing Local Limits

Analysis and Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 7

Table 4-3: How to Prepare a Flow-Proportioned Grab Composite Sample . . . . . . . . . . . . . . . . . . . . . 4 - 10

Table 4-4: Example of a Flow-Proportioned Average

Based on Grab Sample Results and Flow Intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 10

Table 4-5: MDLs (µg/L) for EPA Wastewater Analytical Methods . . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 12

Table 5-1: Options for Managing Sampling Results Below the ML in Removal

Efficiency Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 6

Table 5-2: Suggested Criteria or Standards to be Considered

For Each POC in the Development of AHLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 9

Table 5-3: Land Application Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 15

Table 6-1: Data for Implementation of MAHLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 4

Table 6-2: Options for Allocating and Implementing Local Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 9

List of Exhibits Exhibit 2-1: Example MAHL Determination Based on AHLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 3

Exhibit 2-2: Example MAIL Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 3

Exhibit 3-1: EPA’s 15 POCs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 2

Exhibit 3-2: Pollutants Regulated Under 40 CFR Part 503 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 4

Exhibit 5-1: Be Conservative in Selecting Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 11

Exhibit 5-2: How to Convert Dissolved Metals Criteria to Total Metals Criteria . . . . . . . . . . . . . . . . 5 - 13

Exhibit 5-3: The Challenge in Determining Plant Inhibition Values . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 19

Exhibit 5-4: Inhibition Value Study by Chesterfield County (VA) . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 19

Exhibit 5-5: Less BOD, More Ammonia and Phosphorous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 22

Exhibit 5-6: City of Richland (WA) POTW Evaluates FOG Removal Efficiency . . . . . . . . . . . . . . . 5 - 24

Exhibit 5-7: City of Portland (OR) Uses Current Influent Loading to Develop

Non-Polar FOG Local Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 25

Exhibit 6-1: Safety Factor Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 6

Exhibit 6-2: Background Allocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 10

Exhibit 6-3: Local Limits Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 18

Exhibit 7-1: Why Local Limits Should Be Re-evaluated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 3

Exhibit 7-2: When to Recalculate or Develop Local Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 - 4

Exhibit 7-3: An Example of Changing the Method for Allocating Local Limits . . . . . . . . . . . . . . . . . 7 - 7

List of Equations Equation 5.1: Removal Efficiency Calculated Using Average Daily Removal Efficiency . . . . . . . . . . 5 - 3

Equation 5.2: Removal Efficiency Calculated Using Mean Removal Efficiency . . . . . . . . . . . . . . . . . 5 - 4

Equation 5.3: Plant Removal Efficiency Calculated Using ADRE and Sludge Data . . . . . . . . . . . . . . 5 - 5

Equation 5.4: Plant Removal Efficiency Calculated Using MRE and Sludge Data . . . . . . . . . . . . . . . 5 - 5

Equation 5.5: AHL Based on NPDES Permit Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 11

Equation 5.6: AHL Based on Water Quality Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 12

Equation 5.7: Converting Table 2 Cumulative Loading Rates to Dry Sludge Concentrations . . . . . . 5 - 16

Equation 5.8: Converting Table 4 Annual Loading Rates to Dry Sludge Concentrations . . . . . . . . . 5 - 16

Equation 5.9: AHLs Based on Sludge Land Application and Surface Disposal Criteria . . . . . . . . . . 5 - 17

Equation 5.10: AHLs Based On Secondary Treatment Inhibition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 20

Equation 5.11: AHLs Based On Tertiary Treatment Inhibition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 20 viii

Equation 5.12: AHLs Based On Sludge Digestion Inhibition (Conservative Pollutants) . . . . . . . . . . 5 - 21

Equation 5.13: AHLs Based On Sludge Digestion Inhibition (Non-conservative Pollutants) . . . . . . 5 - 21

Equation 5.14: AHLs Based On Air Criteria and Volatization Rates . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 21

Equation 5.15: AHLs Based On Air Criteria and Existing Emissions . . . . . . . . . . . . . . . . . . . . . . . . 5 - 21

Equation 6.1: Actual Loading vs. MAHL Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 2

Equation 6.2: MAIL Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 4

Equation 6.3: Uncontrolled Loading Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 5

Equation 6.4: IU Contributory Flow Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 11

Equation 6.5: Mass Proportion Method for a Mass-Based Local Limit . . . . . . . . . . . . . . . . . . . . . . . 6 - 11

Equation 6.6: Mass Proportion Method for a Concentration-Based Limit . . . . . . . . . . . . . . . . . . . . . 6 - 11

Equation 6.7: Uniform Allocation of Background Loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 11

Equation 6.8: Uniform Concentration Limit Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 12

List of Figures Figure 2-1: POTW Local Limits Decision Tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 - 2

Figure 3-1: Determining Hauled Waste Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 10

Figure 5-1: Process Flow Diagram for Calculating MAHL for a Single POC . . . . . . . . . . . . . . . . . . . 5 - 2

Figure 5-2: Decile Results for Hypothetical POTW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 4

Figure 5-3: POTW Flow Diagram and Environmental Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 10

Appendices Appendix A - List of Supplemental Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1

Appendix B - Industrial Categories with Pretreatment Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

Appendix C - Pollutants Regulated by Categorical Pretreatment Standards . . . . . . . . . . . . . . . . . . . . . C-1

Appendix D - Clean Water Act Priority Pollutants and the Federal Water Quality Criteria . . . . . . . . . D-1

Appendix E - Federal Sewage Sludge Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E-1

Appendix F - Toxicity Characteristic Leachate Procedure (TCLP) Limitations . . . . . . . . . . . . . . . . . . . F-1

Appendix G - Literature Inhibition Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-1

Appendix H - Closed-cup Flashpoints for Select Organic Compounds . . . . . . . . . . . . . . . . . . . . . . . . H-1

Appendix I - Discharge Screening Levels and Henry’s Law Constants for Organic Compounds . . . . . I-1

Appendix J - OSHA, ACGIH and NIOSH Exposure Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J-1

Appendix K - Landfill Leachate Loadings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . K-1

Appendix L - Hauled Waste Loadings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L-1

Appendix M - Hazardous Waste Constituents - RCRA Appendix VIII . . . . . . . . . . . . . . . . . . . . . . . . M-1

Appendix N - Statistical Approach to Determining Sampling Frequency . . . . . . . . . . . . . . . . . . . . . . . N-1

Appendix O - Minimizing Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . O-1

Appendix P - Methods for Calculating Removal Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . P-1

Appendix Q - Methods for Handling Data Below Detection Level . . . . . . . . . . . . . . . . . . . . . . . . . . . Q-1

Appendix R - Priority Pollutant Removal Efficiencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . R-1

Appendix S - Specific Gravity of Sludge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S-1

Appendix T - Sludge AHL Equations Using Flow (in metric units) . . . . . . . . . . . . . . . . . . . . . . . . . . . . T-1

Appendix U - POTW Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . U-1

Appendix V - Domestic Pollutant Loadings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V-1

Appendix W - Best Management Practices Mini-Case Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . W-1

Appendix X - Region 1, Reassessment of Technically Based Industrial Discharge Limits Checklist . X-1 ix x

ACRONYMS

ACGIH American Conference of Governmental Industrial Hygienists

ADRE Average Daily Removal Efficiency

AHL Allowable Headworks Loading

AMSA Association of Metropolitan Sewerage Agencies

BPJ Best Professional Judgment

BMP Best Management Practice

BOD Biochemical Oxygen Demand

CAA Clean Air Act

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act

CFR Code of Federal Regulations

CIU Categorical Industrial User

CWA Clean Water Act

CWF Combined Wastestream Formula

EPA United States Environmental Protection Agency

FOG Fats, Oils, and Greases

HAP Hazardous Air Pollutant

HEM Hexane Extractable Materials

ICP Inductively Coupled Plasma

IF Interval Flow

IQR Interquartile Range

IU Industrial User

IWS Industrial Waste Survey

I&I Inflow and Infiltration xi

LEL Lower Explosive Limit

MAHL Maximum Allowable Headworks Loading

MAIL Maximum Allowable Industrial Loading

MCL Maximum Contaminant Level

MDL Method Detection Limit

MG Million Gallons

MGD Million Gallons per Day

ML Minimum Level of Quantitation

MLE Maximum Likelihood Estimation

MRE Mean Removal Efficiency

MSDS Material Safety Data Sheet

NAAQS National Ambient Air Quality Standards

NESHAP National Emission Standards for Hazardous Air Pollutants

NIOSH National Institute for Occupational Safety and Health

NPDES National Pollutant Discharge Elimination System

OSHA Occupational Safety and Health Administration

PEL Permissible Exposure Limit

POC Pollutant of Concern

POTW Publicly Owned Treatment Works

PS Percent Solids

QA/QC Quality Assurance/Quality Control

RCRA Resource Conservation and Recovery Act

REL Recommended Exposure Limit

ROS Regression Order Statistic

SGT-HEM Silica Gel Treated Hexane Extractable Materials xii

SIP State Implementation Plan

SIU Significant Industrial User

SUO Sewer Use Ordinance

STEL Short-Term Exposure Limit

TCLP Toxicity Characteristic Leaching Procedure

TLV Threshold Limit Value

TMDL Total Maximum Daily Load

TPH Total Petroleum Hydrocarbons

TRE Toxicity Reduction Evaluation

TSD Technical Support Document

TSS Total Suspended Solids

TWA-TLV Time Weighted Average Threshold Limit Value

UIC Underground Injection Control

VOC Volatile Organic Compound

WET Whole Effluent Toxicity

WQC Water Quality Criteria

WQS Water Quality Standards

WWTP Wastewater Treatment Plant xiii xiv

GLOSSARY

1Q10. The lowest average flow for a one-day period that is expected to occur once every ten years.

1Q10 flows are generally available in the background documentation for the POTW’s NPDES permit and also may be obtained from the local district office of the US Geological Survey (http://water.usgs.gov/local_offices.html).

7Q10. The lowest average flow for a seven-day period that is expected to occur once every ten years.

7Q10 flows are generally available in the background documentation for the POTW’s NPDES permit and also may be obtained from the local district office of the US Geological Survey (http://water.usgs.gov/local_offices.html).

Biochemical Oxygen Demand (BOD). A measurement of the amount of oxygen utilized by the decomposition of organic material, over a specified time period (usually 5 days) in a wastewater sample.

It is used as a measurement of the readily decomposable organic content of wastewater. When five days are prescribed the acronym BOD5 is used.

Allowable Headworks Loading (AHL). The estimated maximum loading of a pollutant that can be received at a POTW’s headworks that should not cause a POTW to violate a particular treatment plant or environmental criterion. AHLs are developed to prevent interference or pass through.

American Conference of Governmental Industrial Hygienists (ACGIH). The American Conference of Governmental Industrial Hygienists is a member-based organization and community of professionals that advances worker health and safety through education and the development and dissemination of scientific and technical knowledge.

Approval Authority. The Director in a NPDES State with an approved State pretreatment program or the appropriate EPA Regional Administrator in a non-NPDES State or NPDES State without an approved State pretreatment program (40 CFR 403.3). The Approval Authority approves POTW pretreatment programs, oversees POTW program implementation, and assumes the responsibility of the Control Authority for those POTWs that do not have a pretreatment program.

Clean Water Act (CWA). The primary Federal law that protects our nation’s waters, including lakes, rivers, aquifers and coastal areas. It provides for the establishment of comprehensive programs that include standards, technical tools, permitting, enforcement and financial assistance to address the many causes of pollution and poor water quality, including municipal and industrial wastewater discharges, polluted runoff from urban and rural areas, and habitat destruction.

Clean Air Act (CAA). The Federal Clean Air Act is the Federal law that forms the basis for the national air pollution control effort. Basic elements of the act include National Ambient Air Quality Standards for major air pollutants, Hazardous Air Pollutants Standards, State attainment plans, motor vehicle emissions standards, stationary source emissions standards and permits, acid rain control measures, stratospheric ozone protection, and enforcement provisions.

Code of Federal Regulations (CFR). A codification of the general and permanent rules published in the Federal Register by the executive departments and agencies of the Federal Government. The CFR is divided into 50 titles, which represent broad areas subject to Federal regulation. EPA’s regulations are in xv

Title 40. Each title is divided into chapters, which usually bear the name of the issuing agency. Each chapter is further subdivided into parts covering specific regulatory areas. Large parts may be subdivided into subparts. All parts are organized in sections, and most citations to the CFR are provided at the section level.

Combined Wastestream Formula (CWF). As defined in 40 CFR 403.6 (e), a procedure under EPA’s pretreatment regulations for calculating alternative discharge limits at industrial facilities where a regulated wastestream from a categorical industrial user is combined with other wastestreams prior to treatment.

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). CERCLA, commonly known as Superfund, was enacted by Congress in 1980. This law created a tax on the chemical and petroleum industries and provided broad Federal authority to respond directly to releases or threatened releases of hazardous substances that may endanger public health or the environment.

Control Authority. As defined in 40 CFR 403.12, the POTW if the POTW’s submission for its pretreatment program (40 CFR 403.3(t)) has been approved in accordance with the requirements of 40 CFR 403.11. If the submission has not been approved, the Control Authority is the Approval Authority.

The Control Authority is responsible for implementing the pretreatment program, including establishment of control mechanisms for compliance assessment and enforcement of national standards, categorical standards, and local limits.

Conservative Pollutants. Pollutants that are presumed not to be destroyed, biodegraded, chemically transformed, or volatilized within the POTW. Conservative pollutants introduced to a POTW ultimately exit the POTW solely through the POTW’s effluent and sludge. Most metals are considered conservative pollutants.

Flashpoint. The lowest temperature at which vapor combustion will propagate away from its source of ignition.

Headworks. The point at which wastewater enters a wastewater treatment plant. The headworks may consist of bar screens, comminuters, a wet well or pumps.

Industrial User (IU). Non-domestic source of pollutants into a POTW regulated under Section 307(b),

(c) or (d) of the Clean Water Act.

Industrial Waste Survey (IWS). The process of identifying and locating industrial users and characterizing their industrial discharges.

Inflow and Infiltration (I&I). Infiltration is the seepage of groundwater into a sewer system, including service connections. Seepage frequently occurs through defective or cracked pipes, pipe joints, connections or manhole walls. Inflow is the water discharged into a sewer system and service connections from sources other than regular connections. This includes flow from yard drains, foundation drains and around manhole covers. Inflow differs from infiltration in that it is a direct discharge into the sewer rather than a leak or seepage into the sewer itself.

Inhibition. Inhibition occurs when pollutant levels in a POTW’s wastewater or sludge cause operational problems for biological treatment processes involving secondary or tertiary wastewater treatment and alter the POTW’s ability to adequately remove BOD, TSS, and other pollutants.

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Interference. EPA uses the term “interference” in its regulations to describe a discharge that, alone or with discharges from other sources, inhibits or disrupts a POTW, its treatment processes and operations, or its sludge processes, use, or disposal and, therefore, causes a violation of the POTW’s NPDES permit, increases the magnitude or duration of such a violation, or prevents the proper use or disposal of sewage sludge in compliance with the Clean Water Act, Solid Waste Disposal Act, Toxic Substance Control Acts, or the Marine Protection, Research and Sanctuaries Act.

Lower Explosive Limit (LEL). The minimum concentration in air at which a gas or vapor will explode or burn in the presence of an ignition source.

Maximum Contaminant Level (MCL). The maximum permissible level of a contaminant in water delivered to any user of a public water system. An MCL is an enforceable standard.

Maximum Allowable Industrial Loading (MAIL). The estimated maximum loading of a pollutant that can be received at a POTW’s headworks from all permitted industrial users and other controlled sources without causing pass through or interference. The MAIL is usually calculated by applying a safety factor to the MAHL and discounting for uncontrolled sources, hauled waste and growth allowance.

Maximum Allowable Headworks Loading (MAHL). The estimated maximum loading of a pollutant that can be received at a POTW’s headworks without causing pass through or interference. The most protective (lowest) of the AHLs (see definition) estimated for a pollutant.

Method Detection Limit (MDL). The minimum concentration of an analyte that can be measured and reported with 99 percent confidence that the analyte concentration is present as determined by a specific laboratory method in 40 CFR Part 136, Appendix B.

Minimum Level of Quantitation (ML). The lowest level at which the entire analytical system must give a recognizable signal and acceptable calibration point for the analyte. It is equivalent to the concentration of the lowest calibration standard, assuming that all method-specified sample weights, volumes, and cleanup procedures have been employed. The ML is calculated by multiplying the MDL by 3.18 and rounding the result to the number nearest (1, 2, or 5) x 10n where n is an integer.

National Ambient Air Quality Standards (NAAQS). Standards established by EPA that apply for outside air throughout the country.

National Institutes for Occupational Safety and Health (NIOSH). The National Institute for Occupational Safety and Health is the Federal agency responsible for conducting research and making recommendations for the prevention of work-related disease and injury. The Institute is part of the Centers for Disease Control and Prevention.

National Pollutant Discharge Elimination System (NPDES). The permitting system established by the Clean Water Act, which regulates the discharge of pollutants into the waters of the United States.

Such a discharge is prohibited unless a NPDES permit is issued by EPA or, where authorized, a State; or a Native American tribal government.

Non-conservative Pollutants. Pollutants that are presumed to be destroyed, biodegraded, chemically transformed, or volatilized within the POTW to some degree.

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Occupational Safety and Health Administration (OSHA). The Occupational Health and Safety Administration is part of the U.S. Department of Labor. It regulates worker conditions and was founded in 1971 to save lives, prevent injuries and protect the health of America’s workers.

Pass Through. A discharge that enters the waters of the United States from a POTW in quantities or concentrations that, alone or with discharges from other sources, either causes a violation of any requirement of the POTW’s NPDES permit, or increases the magnitude or duration of a violation of the POTW’s NPDES permit.

Pollutant of Concern (POC). Any pollutant that might reasonably be expected to be discharged to the POTW in sufficient amounts to pass through or interfere with the works, contaminate its sludge, cause problems in its collection system, or jeopardize its workers.

Pretreatment. As defined in 40 CFR 403.3, “pretreatment” means the reduction of the amount of pollutants, the elimination of pollutants, or the alteration of the nature of pollutant properties in wastewater prior to or in lieu of discharging or otherwise introducing such pollutants into a POTW.

Priority Pollutant. Pollutants listed by the EPA Administrator under Clean Water Act Section 307 (a).

The list of the current 126 Priority Pollutants can be found in 40 CFR Part 423, Appendix A.

Publicly Owned Treatment Works (POTW). A treatment works, as defined by Section 212 of the CWA, that is owned by the State or municipality. This definition includes any devices and systems used in the storage, treatment, recycling, and reclamation of municipal sewage or industrial wastes of a liquid nature. It also includes sewers, pipes and other conveyances only if they convey wastewater to a POTW treatment plant [40 CFR 403.3]. Privately owned treatment works, Federally owned treatment works, and other treatment plants not owned by municipalities are not considered POTWs.

Resource Conservation and Recovery Act (RCRA). Passed by Congress in 1976, RCRA gave EPA the authority to control hazardous wastes from the “cradle to grave.” This includes the generation, transportation, treatment, storage, and disposal of hazardous waste. RCRA also set forth a framework for the management of non-hazardous wastes. The 1986 amendments to RCRA enabled EPA to address environmental problems that could result from underground tanks storing petroleum and other hazardous substances. RCRA focuses only on active and future facilities and does not address abandoned or historical sites (see CERCLA). The Federal Hazardous and Solid Waste Amendments are the 1984 amendments to RCRA that required phasing out land disposal of hazardous waste. Some of the other mandates of this strict law include increased enforcement authority for EPA, more stringent hazardous waste management standards, and a comprehensive underground storage tank program.

Sewer Use Ordinance (SUO). A legal mechanism implemented by a local government entity that sets out, among others, requirements for the discharge of pollutants into a POTW.

Short-Term Exposure Level (STEL). Concentrations to which a worker should not be exposed for longer than 15 minutes and which should not be repeated more than four times per day, with at least one hour between exposures (commonly accepted exposure limits identified by the ACGIH).

Significant Industrial User (SIU). As defined in 40 CFR 403.3, all users subject to Categorical Pretreatment Standards under 40 CFR 403.6 and 40 CFR chapter I, subchapter N; and any other industrial user that discharges an average of 25,000 gallons per day or more of process wastewater to a POTW (excluding sanitary, non-contact cooling and boiler blowdown wastewater); contributes a process xviii wastestream that makes up 5 percent or more of the average dry weather hydraulic or organic capacity of the POTW treatment plant; or is designated as such by the Control Authority defined in 40 CFR 403.12(a) on the basis that the industrial user has a reasonable potential for adversely affecting the POTW’s operation or for violating any pretreatment standard or requirement [in accordance with 40 CFR 403.8(f)(6)].

State Implementation Plan (SIP). An EPA-approved State plan required by the Clean Air Act for the establishment, regulation, and enforcement of air pollution standards.

Time Weighted Average Threshold Limit Value (TWA-TLV). The concentration to which a worker can be exposed for 8 hours per day, 40 hours per week and not have any acute or chronic adverse health effects (commonly accepted exposure limits identified by the ACGIH).

Total Maximum Daily Load (TMDL). Total Maximum Daily Load is a calculation of the maximum amount of a pollutant from point and non-point sources that a waterbody can receive and still meet water quality standards, and an allocation of that amount to the pollutant's sources. The Clean Water Act, Section 303, establishes the water quality standards and TMDL programs.

Total Suspended Solids (TSS). A measure of the suspended solids in wastewater, effluent, or water bodies, determined by tests for “total suspended non-filterable solids.”

Toxicity Characteristic Leaching Procedure (TCLP). A laboratory procedure designed to predict whether a particular waste is likely to leach chemicals into groundwater at dangerous levels. Details are provided in 40 CFR Part 261.

Volatile Organic Compound (VOC). As defined in 40 CFR 50.100, “volatile organic compounds” means any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, which participates in atmospheric photochemical reactions.

Whole Effluent Toxicity (WET) Tests. Whole effluent toxicity is the aggregate toxic effect of an effluent measured directly by an aquatic toxicity test. Aquatic toxicity methods designed specifically for measuring WET have been codified in 40 CFR 136. WET test methods employ a suite of standardized freshwater, marine, and estuarine plants, invertebrates, and vertebrates to estimate acute and short-term chronic toxicity of effluents and receiving waters.

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CHAPTER 1 -

INTRODUCTION

1.1 PURPOSE OF THIS MANUAL

This manual provides guidance to municipalities on the development and implementation of local controls or limits on discharges to publicly owned treatment works (POTWs). This manual replaces the Guidance Manual on the Development and Implementation of Local Discharge Limitations Under the Pretreatment Program issued by the U.S. Environmental Protection Agency (EPA) in December 1987.

The audience for this manual is the POTW personnel responsible for local pretreatment program implementation. The manual provides practical technical assistance and reasoned guidance on the following:

C Determining pollutants of concern (POCs)

C Collecting and analyzing data

C Calculating maximum allowable headworks loadings (MAHLs) for each POC

C Designating and implementing local limits

C Performing local limits reviews and re-evaluations

C Developing local limits to address concerns about collection systems

Appendix A contains a list of supplemental EPA documents to this manual. If a POTW is located in a State with an approved pretreatment program, POTW personnel should also refer to guidance manuals and spreadsheets available from State Approval Authorities.

1.2 LOCAL LIMITS STATUTORY AUTHORITY

A component of the National Pollutant Discharge Elimination System (NPDES) Program, the National Pretreatment Program was developed by EPA to control the discharge of pollutants from POTWs. The statutory authority for the National Pretreatment Program lies in the Federal Water Pollution Control Act of 1972, which was amended by Congress in 1977 and renamed the Clean Water Act (CWA).