2. 1 HEADWORKS ANALYSIS WORKSHOP

3. 2 Objectives of Pretreatment Program Objectives of Pretreatment Program Purpose of Headworks Analysis Purpose of Headworks Analysis Data Needed For Headworks Analysis Data Needed For Headworks Analysis Steps For Headworks Analysis Steps For Headworks Analysis Documents Needed to Submit Headworks Analysis Documents Needed to Submit Headworks Analysis Workshop Overview

4. 3 Protect the Waters of the State (the stream) Protect the POTW’s Microorganisms & WWTP Protect the Land/Groundwater (Sludge) Protect Workers’ Health and Safety Objectives of Pretreatment Program: 40 CFR 403.2 Model SUO, Section 1.1

5. 4 Land Application Standards WWTP Commercial SIUs Aeration Basin Clarifier Disinfection Digester NPDES Permit Limits Water Quality Standards Influent Typicalville Residential

6. 5 40 CFR 403: General Pretreatment Regulations 40 CFR 403.2: Objectives of the General Pretreatment Regulations are to prevent pass through, prevent interference, and improve opportunities to recycle and reclaim sludge. 40 CFR 403.5(c): Each POTW shall develop and continue to develop and enforce local limits. 40 CFR 403.5(c)(4): Local limits can include Best Management Practices (BMPs). 40 CFR 403.5(d): Local limits shall be considered pretreatment standards for purposes of CWA.

7. 6 Purpose of Headworks Analysis Helps POTW meet objectives of 40 CFR 403, including 403.2 and 403.5 Helps POTW meet objectives of 40 CFR 403, including 403.2 and 403.5 Summarizes operating conditions at POTW Summarizes operating conditions at POTW Summarizes POTW’s ability to remove Pollutants of Concern (POCs) Summarizes POTW’s ability to remove Pollutants of Concern (POCs) Calculates: Calculates: Maximum Allowable Headworks Loading Maximum Allowable Headworks Loading Maximum Allowable Industrial Loading Maximum Allowable Industrial Loading Develops site-specific local limits Develops site-specific local limits

8. 7 Categorical Standards VS. Local Limits Categorical standards are developed by EPA Local limits are developed by POTW Categorical standards are uniform Local limits are site- specific Categorical limits are “technology” based – based on SIU treatment technology Local Limits are “technically” based – based on local environmental protection factors

9. 8 Data Needed For HWA Determine HWA Data Time Period Determine HWA Data Time Period DMR & Long/Short Term Monitoring Data DMR & Long/Short Term Monitoring Data POTW Design Data for Conventional Pollutants POTW Design Data for Conventional Pollutants SIUs Load To POTW SIUs Load To POTW Uncontrolled Load To POTW Uncontrolled Load To POTW Sludge Data Sludge Data

10. 9 Define HWA Time Period Based on number of influent and effluent data sets for the least frequently sampled Pollutant of Concern (POC) Division approved LTMP/STMP defines: Proper sampling locations Proper sampling locations Proper pollutants of concern Proper pollutants of concern Correct detection levels Correct detection levels Frequencies Frequencies

11. 10 Full Programs HWA Time Period: Long Term Monitoring Plan To provide adequate data set for HWA: Need at least 12 sets of influent and effluent data for least sampled POC - Need at least 12 sets of influent and effluent data for least sampled POC - Quarterly sampling data for 3 years Quarterly sampling data for 3 yearsOR Monthly sampling data for 1 year Monthly sampling data for 1 year Once define period, use all available data for entire 1 or 3 years, including DMR data Once define period, use all available data for entire 1 or 3 years, including DMR data

12. 11 Modified Programs HWA Time Period: Short Term Monitoring Plan To provide adequate data set for HWA: Need at least 4 sets of influent and effluent data for least sampled POC Need at least 4 sets of influent and effluent data for least sampled POC Quarterly sampling data for 1 year Quarterly sampling data for 1 year To cover all seasons To cover all seasons Once define period, use all available data for entire 1 year, including DMR data Once define period, use all available data for entire 1 year, including DMR data

13. 12 Tab 3-A, page 1C Tab 3-A, page 1C

14. 13 Steps For Headworks Analysis Gather POTW General NPDES Information Collect POTW Design Information Calculate Plant Removal Rates Calculate Allowable Pass Through Load Calculate Allowable Biological Inhibition Load Calculate Allowable Load Using Sludge Criteria Develop Maximum Allowable Headworks Load Calculate SIUs Load to POTW Evaluate Uncontrolled Load to POTW Determine Maximum Allowable Industrial Load Allocate SIU Local Limits

15. 14 Collect Data Calculate RR Calculate Sludge AHL Calculate Inhibition AHL Calculate Pass-Thru AHL Calculate Non-SIU Load Develop MAHL Determine MAIL Reduce Limits Use HASL Review UNC Allocate SIU Limits Over Allocation Done Calculate SIU Load Yes No Headworks Analysis: Flow Diagram

16. 15 Review HWA spreadsheet: Info from NPDES Permit In General Info Section of HWA Tab 3-A, page 2 In General Info Section of HWA Tab 3-A, page 2 NPDES Permit Number – Cell C4 NPDES Permit Number – Cell C4 Tab 3-B, page 11 Tab 3-B, page 11 NPDES Permitted Flow - Cell C7 NPDES Permitted Flow - Cell C7 Tab 3-B, page 13 Tab 3-B, page 13 Stream Classification – Cell C11 Stream Classification – Cell C11 Tab 3-B, page 12 Tab 3-B, page 12

17. 16 Tab 3-B, page 11 Tab 3-B, page 11

18. 17 Tab 3-B, page 12 Tab 3-B, page 12

19. 18

20. 19 Tab 3-A, page 2 Tab 3-A, page 2

21. 20 Review HWA spreadsheet: Info from Program Info Sheet Tab 3A Page 2 Tab 3A Page 2 7Q10 – in mgd – Cell C10 7Q10 – in mgd – Cell C10 Tab 3-B, page 15 Tab 3-B, page 15 Can also find in NPDES fact sheet or from NPDES unit, but will be in cubic feet per second --- must convert to mgd. cfs * 0.646 = mgd Can also find in NPDES fact sheet or from NPDES unit, but will be in cubic feet per second --- must convert to mgd. cfs * 0.646 = mgd Verify Program Info sheet has correct NPDES Permit Number, Permitted Flow, and Stream Classification Verify Program Info sheet has correct NPDES Permit Number, Permitted Flow, and Stream Classification

22. 21 Tab 3-B, page 15 Tab 3-B, page 15

23. 22 Tab 3-A, page 2 Tab 3-A, page 2

24. POTW Removal Rates

25. 24 What Do I Need To Calculate Removal Rates? All DMR and LTMP/STMP data for HWA time period Removal Rate Equation Literature Removal Rates

26. 25 Plant Removal Rates Calculation Removal Rate equation: Using unpaired sampling data Mean Removal Rate, RR = ((C I - C E )/ C I ) * 100 RR = Removal Rate, % C I = Average Influent Concentration, mg/l C E = Average Effluent Concentration, mg/l Methodologies: Unpaired sampling (Division recommends) Paired sampling Decile approach

27. 26 Plant Removal Rates Calculation Use DMR data - Tab 3-B, pages 16 and 17 To calculate average POTW flow To calculate average influent and effluent of BOD, TSS, and any other available pollutants If have Below Detection Level (BDL) data… and that BDL was treated as zero when calculating DMR Monthly Ave…. must recalculate DMR Monthly Average using ½ detection level

28. 27 Plant Removal Rates Calculation Tab 3-B, pages 16 and 18 Use LTMP/STMP data for rest of metals and other POCs: Tab 3-B, pages 16 and 18 Non-NPDES limits page POCs Influent If Below Detection Level (BDL) data, enter “<“ sign in “<“ column, and detection level in other cell

29. 28 Tab 3-B, page 16

30. 29 Tab 3-B, page 16

31. 30 Tab 3-B, page 19

32. 31 Tab 3-B, page 16

33. 32 Tab 3-B, page 23

34. 33 Tab 3-B, page 17

35. 34 Tab 3-B, page 17

36. 35 Tab 3-B, page 19

37. 36 Tab 3-B, page 17

38. 37 Tab 3-B, page 17

39. 38 Tab 3-B, page 23

40. 39 Tab 3-B, page 18

41. 40 Tab 3-B, page 23

42. 41 Removal Rate Calculations Enter data for every month and every LTMP/STMP sample for the whole HWA Data Time Period If update spreadsheet as receive LTMP/STMP results each quarter: less typing at HWA time verify met LTMP/STMP Detection Levels (DLs)… …and get sample re-analyzed before lab tosses sample can review trends in data, outliers, etc.

43. 42 Tab 3-B, page 23-24

44. 43 Tab 3-B, page 24

45. 44 When Do I Use Literature RRs? More than 50% of data collected is below detection level Small or a misrepresentative data set Any Questions? Call PERCS or Consult The Comprehensive Guidance for Pretreatment Programs in North Carolina, Chapter 5, Section 5-D, page 1

46. 45 Tab 1, yellow page Cyanide Literature Removal Rate 69%

47. 46 Tab 3-B, page 24

48. 47 Review HWA spreadsheet Tab 3-A, page 2 Tab 3-A, page 2 Average POTW Flow in cell C8 Average POTW Flow in cell C8 Removal Rates in column C Removal Rates in column C Removal Rate Sources in column D Removal Rate Sources in column D

49. 48 Tab 3-A, page 2

50. 49 Tab 3-A, page 2

51. 50 Tab 3-A, page 1C Tab 3-A, page 1C

52. 51 Removal Rate Guidance in Tab 1 of your Manual Removal Rate Guidance in Tab 1 of your Manual Unit Conversion Guidance in Tab 1 of your Manual Unit Conversion Guidance in Tab 1 of your Manual

53. 52 Land Application Standards WWTP Commercial SIUs Aeration Basin Clarifier Disinfection Digester NPDES Permit Limits Water Quality Standards Influent Typicalville Residential

54. 53 Three Limiting Criteria for Developing Maximum Allowable Headworks Load 1. 1. Pass Through a. NPDES Limit b. NC-Water Quality Standard c. Design 2. Biological Processes Inhibition a. Activated Sludge/Nitrification Inhibition b. Anaerobic Digester Inhibition 3. Sludge Quality - 503 Regulations a. Land Application b. Incinerator C. Landfill

55. 54 Pass Through Criteria NPDES Limit NC-Water Quality Standard

56. Limiting Criteria Pass Through Aeration Basin Sludge Chlorine/ UV Disinfect Aeration Basin Clarifier Bar Screen Grit Removal Filter Digester 1a River Styx 1b 1c

57. 56 What Do I Need To Calculate Pass Through Allowable Headworks Load (AHL)? Current NPDES Permit – Tab 3-B, pages 11-14 Which parameters are limited? New NPDES limits expected/drafted? NC-Water Quality Standards - Tab 1 - yellow All parameters not limited in your NPDES Receiving Stream Classification Pass Through Equation Removal Rates – Tab 3-B, pages 19-28 Average POTW Flow (NOT Permitted flow)

58. 57 AHL: Pass Through Criteria Based on NPDES Limit Allowable Headworks Loading (AHL) based on Passthrough/NPDES = NPDES POTW Average (8.34) Limit, mg/l Flow, mgd (1 - POTW RR, as decimal)

59. Simple Pass Through Example based on NPDES Permit Limit NPDES Permit Limits Water Quality Standards Land Application Standards WWTP SIU’s Residential Commercial 2 mg/l Influent 50% RR NPDES Permit Limit= 1 mg/l The other “1 mg/l” went into the sludge

60. Another Simple Pass Through Example based on NPDES Permit Limit NPDES Permit Limits Water Quality Standards Land Application Standards WWTP SIU’s Residential Commercial 4 mg/l Influent 75% RR The other “3 mg/l” went into the sludge NPDES Permit Limit= 1 mg/l

61. 60

62. 61

63. 62 AHL: Pass Through Criteria Based on Typicalville’s Mercury NPDES Limit Allowable Headworks Loading (AHL) based on Passthrough/NPDES = (8.34) ( 0.000224 ) ( 7.168 ) = (1 – 0.60) 0.03348 lbs/day mercury allowed at influent and not violate NPDES

64. Pass Through for Mercury - based on Typicalville’s NPDES Permit Limit NPDES Permit Limits Water Quality Standards Land Application Standards WWTP SIU’s Residential Commercial 0.00056 mg/l (560 ng/l) (0.03348 #’s/day) Influent 7.168 MGD 60% RR NPDES Permit Limit= 0.000224 mg/l (224 ng/l)

65. 64 Review HWA Spreadsheet Tab 3-A, page 2 NPDES Limits in column B If have more than one limit for same parameter, enter most stringent. Consider entering potential new NPDES limits? Watch Units – 50 ug/l limit = 0.05 mg/l 224 ng/l limit = 0.000224 mg/l Pass through NPDES AHLs calculated in Column E

66. 65 Tab 3-A, page 2

67. 66 AHL: Pass Through Criteria Based on Water Quality Standard Allowable Headworks Loading (AHL) based on Pass Through/WQS = NC Water Quality POTW Receiving Standard, Average + Stream (8.34) mg/l Flow, mgd 7Q10, mgd (1 - POTW RR, as decimal)

68. 67 Tab 1, yellow page Nickel has two Standards! Which do I use? 0.088 mg/l Class C-Aquatic Life? 0.025 mg/l Class WS-Water Supply?

69. 68 Which Stream Standard? Receiving Stream Classification Class C – Use “Aquatic Life” Class Water Supply (WS) and Trout – Use WS/Trout if available. Otherwise use Aquatic Life High Quality Waters (HQW), Outstanding Resource Waters (ORW), or any with a “+” or “Critical Area” - Contact PERCS

70. 69 Which Stream Standard? Tab 3-B, page 12 - Typicalville is Class Water Supply IV Tab 3-A, page 2, cell C11 Tab 1 – HWA numbers Nickel – 25 ug/l (Class C = 88 ug/l) Arsenic – 10 ug/l (Class C = 50 ug/l) Chlorides – 250 mg/l versus 230 mg/l Action Level for Class C Sulfates – 250 mg/l Tab 3A, page 2, “comment boxes” for cells F27-F38

71. 70 AHL: Pass Through Criteria Based on Nickel Water Quality Standard Allowable Headworks Loading (AHL) for Nickel based on Pass Through/WQS = (8.34)(0.025 mg/l)(7.168+239.02 mgd)= (1 – 0.42) 88.5 lbs/day nickel allowed at influent to not violate NC WQS for Water Supply

72. 71 Review HWA Spreadsheet Tab 3-A, page 2 Stream Standards in column F If more than one Standard for same parameter – eval. rec. stream class. Do not enter standards where have NPDES Permit Limits Stream Standard Sources in column G If your POC is not on PERCS HWA Numbers sheet, contact PERCS Pass through Water Quality Stream Standard AHLs calculated in Column H

73. 72 Tab 3-A, page 2

74. 73 Action Level POCs Action Level Parameters in NC are: Copper, Silver, Zinc, Fe, and Chlorides Do not enter WQ Action Levels for Action Level Parameters, UNLESS The POTW is failing Toxicity and an Action Level Pollutant is the cause for failing. ….Remember, for Water Supply receiving streams, Chlorides is Water Quality Standard, so must enter in HWA if Chlorides is POC for your POTW

75. 74 Tab 3-A, page 2

76. 75 What If 7Q10 Flow = Zero? Typicalville has huge river– 7Q10 = 239.02 MGD Allowable Headworks Loading (AHL) for Nickel based on Pass Through/WQS AHL = (8.34)(0.025)(7.168 + 239.02) (1 – 0.42) (1 – 0.42) AHL = 88.5003 lbs./day What if your 7Q10 were Zero? AHL = (8.34)(0.025)(7.168 + 0) (1 – 0.42) (1 – 0.42) AHL = 2.5678 lbs./day

77. 76 Tab 3-A, page 2

78. 77 Design

79. 78 AHL: Conventional/Design Pollutants The engineers who designed your POTW designed it to be able to treat a specific target or “design” influent value for selected parameters and still meet your NPDES limit. Most/all POTWs have Design for BOD+TSS Some/many have Design for NH3 Some/fewer have Design for Total Phosphorus (TP), and maybe even Total Nitrogen (TN)

80. 79 AHL: Conventional/Design Pollutants Where are my Design values? O&M Manual Plans and Specs Engineer’s Calculations Tab 3-B, page 29 What about: Upgrades Expansions New design parameters AHL = AHL Design = (8.34)(Design Influent, mg/l) (Design flow, MGD) Use average Design values, not max or peak

81. 80 Tab 3-B, page 29 Tab 3-B, page 29

82. 81 Review HWA Spreadsheet Tab 3-A, page 2 Design Criteria in cells G17 – G21 If have more than one Design Criteria for same parameter, enter most stringent If your Design POC is not in HWA spreadsheet, contact PERCS Design AHLs calculated in Column I

83. 82 Tab 3-A, page 2 Tab 3-A, page 2

84. 83 AHL: Conventional/Design Pollutants All NC POTWs must enter Design Criteria in HWA for all parameters with Design Criteria Then evaluate Design Load and compare to the NPDES Load, in both mg/l and lbs/day NPDES < Design, use NPDES as MAHL May be able to use Design if under-loaded Contact PERCS to discuss Design < NPDES, use Design as MAHL Remember that’s all MAHL you will ever have Not happy? - More in a minute To select Design as MAHL, put X in cells J17–J21 Tab 3-A, page 2

85. 84 Tab 3-A, page 2 Tab 3-A, page 2

86. 85 AHL: Conventional/Design Pollutants Sometimes a WWTP can actually treat wastewater better than the design criteria set by the engineer. MAHL > Design Criteria may be approved with: Design Multiplier of 1.5 Historic Data => Design Load? NC Professional Engineer provides new Stamped Design Calculations Other Compelling Argument?

87. 86 AHL: Conventional/Design Pollutants Specific guidance on web-site NOW! And in Tab 1 of your Manual Feb 2007, Dec 2007, Dec 2008 Applies to BOD, TSS, NH3, and Phosphorus Recommend apply to Total Nitrogen

88. 87 AHL: Conventional/Design Pollutants - Typicalville Typicalville used the Design Multiplier of 1.5 See discussion in HWA Narrative Tab 3-A, page 1C

89. 88 Tab 3-A, page 1C Tab 3-A, page 1C

90. 89 Tab 3-A, page 2 Tab 3-A, page 2

91. 90

92. Biological Processes Inhibition Aeration Basin

93. Limiting Criteria Biological Process Inhibition Aeration Basin Sludge Chlorine/ UV Disinfect Aeration Basin Clarifier Bar Screen Grit Removal Filter Digester 2a and 2b River Styx 2c

94. 93 What Do I Need To Calculate Biological Inhibition Load? Basic understanding of WWTP microorganisms Wastewater Biological Treatment Units Activated Sludge, Aeration Basin, etc. Trickling Filter Carbonaceous vs. Nitrogenous/Nitrification Sludge Biological Treatment Units Only if have Anaerobic Digester Inhibition Formula Literature Inhibition Criteria LTMP/STMP data from basins (+anaerobic digesters)

95. 94 AHL: Inhibition Criteria Based on Activated Sludge/Nitrification Allowable Headworks Loading (AHL) based on Secondary Treatment Inhibition = Secondary Inhibition POTW Average (8.34) Criteria, mg/l Flow, mgd (1 - Primary RR, as decimal) No primary Clarifiers? - just use 0

96. Water Quality Standards Inhibition Loading for Nickel based on Nitrification Inhibition NPDES Permit Limits WWTP SIU’s Residential Commercial 0.25 mg/l (14.9453 #/ day) Influent 7.168 MGD Activated Sludge Land Application Standards

97. 96 Tab 1, yellow page Nickel has two numbers! Which do I use? 1 mg/l Activated Sludge? 0.25 mg/l Nitrification?

98. 97 Which Inhibition Values Do I Use? Activated Sludge Inhibition: All POTWs must evaluate for Activated Sludge Inhibition Nitrification Inhibition: POTWs who have Ammonia limit and/or Nitrogenous bacteria (We’ll get to anaerobic digesters later…)

99. 98 Which Inhibition Values Do I Use? Nitrification Inhibition: NPDES permit limit for ammonia Tab 3-B, page 13 Nitrogenous bacteria Does LTMP data suggest WWTP nitrifies? Tab 3-B, page 20 Ask the ORC - Does POTW nitrify? Must use lower of Activated Sludge or Nitrification Inhibition Criteria

100. 99

101. 100 Tab 3-B, page 20 Tab 3-B, page 20

102. 101 Review HWA Spreadsheet Tab 3-A, page 3 Enter chosen inhibition criteria in column D Source in Column E If your POC is not on PERCS HWA Numbers sheet, contact PERCS

103. 102 Tab 3-A, page 3 Tab 3-A, page 3

104. 103 No Literature Inhibition Criteria Load? If no literature Biological Inhibition criteria for a POC, do not have to develop site-specific inhibition criteria L/STMP - Do not have to sample for these POCs at the biological process locations such as aeration basin or influent to anaerobic digester or other inhibition related locations like primary clarifier effluent BOD, TSS, Mo, Se, some others

105. 104 Site Specific vs. Literature Inhibition Criteria If LTMP data suggests POTW is acclimated to higher levels of site-specific concentration than traditional literature values, ask ORC: Was POTW upset during basin sampling? Were there NPDES or Toxicity violations? Were any effluent parameters (usually BOD, TSS NH 3 ) elevated above normal for no other apparent reason? Was there foaming? Was there fluctuations in the DO? Did the bugs die? If No, then the POTW may consider using basin data for site specific inhibition criteria.

106. Tab 3-B, page 30-31 Tab 3-B, page 30-31

107. 106 Tab 1, yellow page

108. 107

109. 108 Review HWA Spreadsheet Tab 3-A, page 3 Replace chosen literature inhibition criteria in column D with chosen site-specific value. Source in Column E, and discuss in HWA Narrative

110. 109 Tab 3-A, page 3 Tab 3-A, page 3

111. 110 Tab 3-A, page 1C Tab 3-A, page 1C

112. 111 Get Credit for Primary Clarifier Removal? Quarterly LTMP/STMP sampling at primary clarifier effluent (PCE) Sample before any return flows Same detection levels as influent/effluent Only required for parameters with literature inhibition criteria Use with WWTP influent data to calculate primary removal rates BDL Data? – same as WWTP removal rates regarding use of literature removal rates No PCE sampling? No primary removal rates in HWA at all, even literature primary removal rates Newton Example HWA – Tab 4 – has primaries

113. 112 AHL: Based on Anaerobic Digester Inhibition Conservative Pollutants AHL for Anaerobic Digester = (8.34)(An. Dig Inhib Crit, mg/l) (Flow to Dig, MGD) POTW Removal Rate, as Decimal Non-conservative Pollutants AHL for Anaerobic Digester = (Influent NH3 in lbs/day) * (An. Dig Inhib Crit, mg/l) (Avg. influent to sludge to An. Dig NH3, mg/l) AnaerobicDigester

114. 113 Tab 1, yellow page

115. 114 Review HWA Spreadsheet [On Tab 3-A, page 2, enter sludge to Digester Flow in cell C14] Tab 3-A, page 3 Literature inhibition criteria in column G Source in Column H Ammonia is Special… Non-conservative – not all NH3 “removed” by WWTP ends up in digester…. is converted to NO2/NO3 Average influent NH3 in cell G49 Average Influent to Sludge to Digester NH3 in cell G50

116. 115 Tab 3-A, page 2 Tab 3-A, page 2

117. 116 Tab 3-A, page 3 Tab 3-A, page 3

118. Sludge Criteria – 503 Regulations

119. HWA Limiting Criteria Sludge 503 Regulations Aeration Basin Sludge Chlorine/ UV Disinfect Aeration Basin Clarifier Bar Screen Grit Removal Filter Digester 3a 3b River Styx

120. 119 Tab 3-C Copy of selected pages of current Sludge Permit Copy of selected pages of current Annual Sludge Report Site Life Sludge Formulas What Do I Need To Calculate Sludge Load?

121. 120 Land Application/Compost: Limits: Arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, zinc Incineration: Limits: Arsenic, beryllium, cadmium, chromium, lead, mercury, nickel Municipal Solid Waste Landfill: No pollutants limits. Requirements in 40 CFR 257, 258, and 261 apply. Sludge use and disposal methods

122. 121 Allowable Headworks Loading (AHL) based on Sludge Ceiling Limits = Sludge Percent Sludge Ceiling Solids as average mgd (8.34) Limit, mg/kg decimal to disposal (POTW RR as decimal) Tab 3-C, pages 34-43 - Sludge Specific Gravity assumed to be 1, same as water. - Yours significantly different? Contact PERCS AHL: Based on Land App/Compost Using Ceiling Concentration Limits

123. Water Quality Standards Sludge Loading for Nickel - based on Ceiling Sludge Loading NPDES Permit Limits WWTP SIU’s 42% RR Residential Commercial 0.164 mg/l (9.7978 #/ day) Influent 7.168MGD Land Application Standards Digester Given: 420 mg/kg std. from permit 1164.9 acres permitted 4.4 % solids 0.0267 MGD flow to disposal SIUs

124. 123 Allowable Headworks Loading (AHL) based on Cumulative Sludge Limit = (CAR in lbs/acre)(SA in acres) (SL, years)(POTW RR as decimal)(365 days/year) (Cumulative Applic. Limit)(Total Permitted Acres) (Site Life)(Removal Rate)(365/year) Tab 3-C, pages 34-43 AHL: Based on Land Application Using Cumulative App Limit

125. 124 Tab 3-C, page 36 Tab 3-C, page 36

126. 125 Tab 3-C, page 37 Tab 3-C, page 37

127. 126 Tab 3-C, page 38 Tab 3-C, page 38

128. 127 Tab 3-C, page 39 Tab 3-C, page 39

129. 128 If Attachment A of Sludge Permit shows sources in addition to WWTP for this HWA, acres in Attachment B must be adjusted accordingly. Discuss in HWA Narrative. Tab 3-C, page 40 Tab 3-C, page 40

130. 129 If Attachment A of Sludge Permit shows sources in addition to WWTP for this HWA, acres in Attachment B must be adjusted accordingly. Discuss in HWA Narrative. Tab 3-C, page 41 Tab 3-C, page 41

131. 130 Tab 3-C, page 42 Tab 3-C, page 42

132. 131 Tab 3-C, page 43 Tab 3-C, page 43

133. 132 Review HWA Spreadsheet Column C – Tab 3-A, page 2 – Enter values for: Sludge Permit Number Class of Sludge Disposal A for Compost; B for Land App Sludge Flow and % Solids to Disposal Sludge Site Acres and Site Life Tab 3-A, page 4 Spreadsheet automatically selected sludge standards based on A or B Spreadsheet calculated sludge AHLs

134. 133 Review HWA Spreadsheet Site Life – Cell C18 – Tab 3-A, page 2 Can calculate by dividing annual load on most heavily loaded field by cumulative limit Will likely get very large value - 100-500 years If use this value in HWA, will likely get very small Cumulative Sludge AHL Most POTWs use 20 to 50 years

135. 134 Tab 3-A, page 2 Tab 3-A, page 2

136. 135 Tab 3-A, page 4 Tab 3-A, page 4

137. 136 Tab 1 Tab 1

138. Notice To Composters! The previous example was for land applied sludge or “Class B” If you compost your sludge, also called “Class A” or “Distribution and Marketing,” entering “A” in cell C13 will automatically adjust Tab 3-A page 4 of HWA worksheet to use the applicable standards

139. 138 AHL: Based on Incineration Contact PERCS to discuss requirements

140. Determines the Amount of Pollutant the POTW can Treat Based on the Most Restrictive Criteria

141. 140 Review HWA Spreadsheet Tab 3-A, page 5 Final AHLs for each criteria shown Pass Through / Design Inhibition Sludge Smallest one is chosen as the – Maximum Allowable Headworks Loading (MAHL)

142. 141 Tab 3-A, page 5 Tab 3-A, page 5

143. 142 Land Application Standards WWTP SIUs Aeration Basin Clarifier Disinfection Digester NPDES Permit Limits Water Quality Standards Influent Uncontrollable Load Residential Commercial Non-SIUs

144. 143 Determine Uncontrolled Load Everything that contributes to POTW not covered in SIU Permit Everything that contributes to POTW not covered in SIU Permit Residential Residential Non-Residential, but not SIU, for example: Non-Residential, but not SIU, for example: Commercial Commercial Hospitals, Funeral Homes Hospitals, Funeral Homes Doctors, Dentists Doctors, Dentists Car Repair/Wash Centers Car Repair/Wash Centers Inflow/Infiltration Inflow/Infiltration ALL Non-SIUs ALL Non-SIUs

145. 144 Uncontrolled load may be determined in two ways: Mass Balance Method Sum of SIU Load for each POC Subtract total SIU Load from POTW Influent Load Sampling Method Sample for uncontrolled pollutants per LTMP

146. 145 Average Influent values from Removal Rate Spreadsheet – Tab 3-B, pages 19-28 Average SIU values from SIU Data summaries – Tab 3-D, pages 52-84 Average Uncontrollable values from Uncontrollable data summary, if available [N/A for Typicalville] SlU Uncontrollable Mass Balance Spreadsheet – Tab 3-D, pages 48-51 What Do I Need To Calculate Uncontrollable Load?

147. 146 Review Mass Balance Spreadsheet Tab 3-D, pages 48-51 Enter Average SIU flow and mg/l values Tab 3-D, pages 52-84 Enter Average POTW flow and Average Influent mg/l values in row 21 Tab 3-B, pages 19-28 Enter Uncontrollable mg/l values If available Compare uncontrollable mass balance, sampling, and literature values Choose one to be used in HWA…

148. 147 Tab 3-D, page 48 Tab 3-D, page 48

149. 148 Tab 3-D, page 49 Tab 3-D, page 49

150. 149 Choosing Uncontrollable Value to be used in HWA …compare uncontrollable mass balance, sampling, and literature values… …and choose one for HWA? Which one is more… Reasonable? Representative? Conservative? Remember, for uncontrollable, “larger” is more conservative

151. 150 Uncontrolled Mass Balance Troubleshooting Inaccurate flow or pollutant data In particular, SIU flow data Limited data set Widely variable detection levels Inflow and Infiltration Degradation of the pollutant in the collection system Conservative/non conservative pollutant

152. 151 Uncontrollable Sampling Troubleshooting Sample location not really “uncontrolled” 1 house and 27 restaurants new subdivision (low flow toilets, no sewer leaks) No commercial and/or non-SIU Inaccurate sample collection May need >1 sampling point or larger data set Flow may be too low BOD will degrade in the collection system

153. 152 Review Spreadsheets Chose uncontrollable values to be used in HWA Tab 3-D, pages 48-51 Enter Uncontrollable flow in cell C9 Tab 3-A, page 2 of HWA Spreadsheet Enter chosen uncontrollable values and sources to HWA Spreadsheet Tab 3-A, page 6, columns E and F

154. 153 Tab 3-D, page 49 Tab 3-D, page 49

155. 154 Tab 3-A, page 2 Tab 3-A, page 2

156. 155 Tab 3-A, page 6 Tab 3-A, page 6

157. 156 Tab 3-A, page 1C Tab 3-A, page 1C

158. Uncontrollable As Zero   If all of the influent data for a particular pollutant of concern is all less than the current best available detection level.   If the program does sampling of the collection system and sample results less than the current best detection level can be averaged as zeros. 157

159. Uncontrollable As Zero Cont. Arsenic -2.0 µg/L Cadmium – 0.50 ug/l Chromium - 10 µg/L Copper – 2.0 µg/L Lead - 2.0 µg/L Mercury – 1.0 ng/L (EPA Method 1631E) Molybdenum - 10 µg/L Silver – 1.0 µg/L Selenium - 5.0 µg/L Zinc - 10 µg/L * Red Highlighted are lower than the current model LTMP/STMP 158

160. Uncontrollable As Zero Cont.   There may be other circumstances under which the uncontrollable concentration can be considered zero but they will be evaluated on a case-by- case basis. 159

161. Determines the Amount of MAHL Available to your Industries

162. 161 Maximum Allowable Industrial Loading (MAIL) MAIL = Maximum Allowable Industrial Loading, lbs/day MAIL = Maximum Allowable Industrial Loading, lbs/day MAHL = Maximum Allowable Headworks Loading, lbs/day MAHL = Maximum Allowable Headworks Loading, lbs/day SF = Safety Factor, if desired SF = Safety Factor, if desired MAIL= MAHL – UNC Load - SF

163. 162 Review HWA Spreadsheet Tab 3-A, page 6 MAILs calculated in column H Any negative numbers? Typicalville - None so far….

164. 163 Tab 3-A, page 6 Tab 3-A, page 6

165. Allocating The MAIL To Your Industries SIU’s

166. Example Allocation Nickel

167. 166 NPDES Permit Limits Water Quality Standards Sludge Standards WWTP Residential 42% RR 0.1229 lbs./day (4.1 ugl @ 3.594 MGD) combined Uncon. 3.6 MGD Allocating Nickel Allocating Nickel 9.8 lbs/ day Influent - based on Sludge Ceiling 7.168 MGD SIU #3 Commercial SIU #1 SIU #2 0.9925 lbs.day (2.38 mg/l @ 0.05 MGD) 0.85 MGD

168. 167 Review Allocation Table Click on “AT” tab in lower left corner AT Worksheet within HWA_AT workbook Tab 3-A, pages 7-10 MAHLs, Basis for MAHL, Uncontrollable Loads, and MAILs automatically filled in from HWA worksheet Enter SIU info + permit limits in Row 12 Review MAIL left in Row 20 Any negative numbers?

169. 168 Tab 3-A, page 7 Tab 3-A, page 7

170. 169 Safety Factor / MAHL Reserve Tab 3-A, pages 7-10 Row 29 - % MAIL still available Row 30 - % MAHL still available Buffer against SIU IUP violations Uncertainty in HWA calculations Reserve for future growth Especially for POCs based on Design

171. Example Allocation Cyanide

172. 171 Tab 3-A, page 8 Tab 3-A, page 8

173. 172 Generally Should you be over allocated? For example, if MAHL based on NPDES limit, are you violating that limit? Any typos, missing/changed formulas? Review your choices for all values Did you have other choices to make? Can you lower SIU limits (pollutant or flow)? What Do I Do When I’m Over Allocated?

174. 173 Specifically Stream Standard Limiting for copper, silver, zinc? If yes, can you delete Action Levels? Is Inhibition Limiting? If yes, can you use site-specific Inhibition criteria? Is Sludge Limiting? If yes, can you lower site life? Can you perform HASL Worksheet? What Do I Do When I’m Over Allocated?

175. 174 Should Typicalville be over allocated? Arsenic MAHL based on sludge ceiling Are they violating that limit? Tab 3-C, page 37 and 43 If no, can they perform HASL Worksheet? Can/should they lower SIU limits (pollutant or flow)? Typicalville Over Allocated for Arsenic

176. 175 Tab 3-C, page 37 Tab 3-C, page 37

177. 176 Tab 3-C, page 43 Tab 3-C, page 43

178. Headworks Addendum for Sludge Loading

179. 178 HASL Worksheet Re-evaluates AHL for Sludge Criteria by taking into consideration: 1.Historical WWTP Performance Data, 2.Historical Sludge Report Data, and 3.Applicable Sludge Criteria Only applicable for pollutants over allocated based on sludge criteria!

180. 179 What Do I Need For A HASL? Copy of current Sludge Permit Copy of current Annual Sludge Report POTW Influent Data from Removal Rate Calculations HASL Worksheet and Calculations

181. 180 HASL – Step 1 - Arsenic Cumulative Criteria Check POC to assure that the available land does not exceed 80% of the Cumulative Loading Rate. Actual Cumulative Load From Actual Cumulative Load From Most Heavily Loaded Field *(100) <= 80% Most Heavily Loaded Field *(100) <= 80% Cumulative Sludge Loading Limit For the Pretreatment World, the “most heavily loaded field” is the field with the highest cumulative lbs/acre for that pollutant.

182. 181 HASL – Step 1 From current Annual Sludge Report, locate Land Application Field Summary Reports. Review “Cumulative lbs/acre” values for HASL POC for each field. Identify field with highest cumulative lbs/acre for HASL POC – Pretreatment’s “most heavily Loaded field” Enter value in column C of HASL worksheet in HWA_AT workbook (spreadsheet) Any flags? Contact PERCS

183. 182 Field RC 00123 0002 has 0.186 lbs/acre of arsenic land applied so far. Is there another field with more arsenic? Tab 3-C, page 45 Tab 3-C, page 45

184. 183 Field RC 00123 0001 has 0.466 lbs/acre of arsenic. Note also most heavily loaded for copper and mercury. Tab 3-C, page 46 Tab 3-C, page 46

185. 184 Tab 3-C, page 47 Tab 3-C, page 47

186. 185 HASL – Step 2 - Arsenic Ceiling Criteria Check POC to assure that sludge does not exceed 80% of the Sludge Ceiling Limit Maximum mg/kg Maximum mg/kg from Sludge Report *(100) <= 80% from Sludge Report *(100) <= 80% Sludge Ceiling mg/kg Limit Sludge Ceiling mg/kg Limit

187. 186 HASL – Step 2 From current Annual Sludge Report, locate Annual Residual Sampling Summary Forms Review “mg/kg dry weight” values values for HASL POC for each sample. Identify highest “mg/kg dry weight” Enter value in column H of HASL worksheet in HWA_AT workbook (spreadsheet) Any flags? Contact PERCS

188. 187 8/1/07 sample highest arsenic – 7.3 mg/kg. Note 8/1/07 also has highest for cadmium, molybdenum, and selenium. Tab 3-C, page 43 Tab 3-C, page 43

189. 188 Tab 3-C, page 47 Tab 3-C, page 47

190. 189 HASL – Step 3 - Arsenic Recalculate Sludge HASL AHL A new Sludge AHL is calculated using historical POTW influent and % of Ceiling Concentration AHL based on Sludge/HASL = Average Influent Loads, lbs/day Average Influent Loads, lbs/day % of ceiling mg/kg Limit % of ceiling mg/kg Limit based on highest sludge sample based on highest sludge sample

191. 190 HASL – Step 3 Locate HWA Removal Rate Calculations Identify Average Influent value for HASL POC Enter value in column M of HASL worksheet in HWA_AT workbook (spreadsheet) HASL Spreadsheet will calculate HASL sludge AHL

192. 191 Tab 3-B, page 22 Tab 3-B, page 22

193. 192 Tab 3-C, page 47 Tab 3-C, page 47

194. 193 Now What? Does HASL indicate Flags? If yes, must do Metals Management plan - contact PERCS Are there any sludge violations? If yes, cannot use Sludge/HASL AHL – contact PERCS If no flags and no sludge violations - you can use Sludge/HASL AHL!

195. 194 Review HWA worksheet HWA worksheet Tab 3-A page 6 - Enter “X” in column D for HASL POC. HWA worksheet Tab 3-A page 4 - New HASL MAHL automatically appears in columns D, H, and/or I as applicable HWA worksheet Tab 3-A page 5 – worksheet chooses new MAHL Review Tab 3-A page 6 and AT Over Allocation Resolved?

196. 195 Tab 3-A, page 6 Tab 3-A, page 6

197. 196 Tab 3-A, page 4 Tab 3-A, page 4

198. 197 Tab 3-A, page 8 Tab 3-A, page 8

199. 198 Tab 3-A, page 1C Tab 3-A, page 1C

200. 199 Collect Data Calculate RR Calculate Sludge AHL Calculate Inhibition AHL Calculate Pass-Thru AHL Calculate Non-SIU Load Develop MAHL Determine MAIL Reduce Limits Use HASL Review UNC Allocate SIU Limits Over Allocation Done Calculate SIU Load Yes No Headworks Analysis: Flow Diagram

201. 200 Transmittal Letter Transmittal Letter Organized Data Summaries Organized Data Summaries DMR/LTMP/STMP, SIU, Uncontrolled DMR/LTMP/STMP, SIU, Uncontrolled Related LTMP sampling Related LTMP sampling Removal Rates Calculation spreadsheet Removal Rates Calculation spreadsheet HWA.AT.HASL spreadsheet HWA.AT.HASL spreadsheet Documents Needed to Submit HWA

202. 201 Mass Balance spreadsheet Mass Balance spreadsheet Plant Design Documentation Plant Design Documentation Copy of applicable pages from Land Application or Composting permit Copy of applicable pages from Land Application or Composting permit Copy of applicable parts of sludge report Copy of applicable parts of sludge report Explanation/Discussion of Choices, Assumptions, etc. Explanation/Discussion of Choices, Assumptions, etc. Documents Needed to Submit HWA

203. 202 Division Pretreatment Contacts Monti Hassan: (919) 807-6314 Sarah Morrison Bass: (919) 807-6310 Deborah Gore:(919) 807-6383 FAX:(919) 807-6489 Email: firstname.lastname@ncdenr.gov Physical Address: 1617 Mail Service Center Raleigh, NC 27699-1617 Website: http://portal.ncdenr.org/web/wq/swp/ps/pret