UNDERSTANDING THE BASIS OF POTW LOCAL POLLUTANT DISCHARGE LIMITATIONS

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UNDERSTANDING THE BASIS OF POTW LOCAL POLLUTANT
DISCHARGE LIMITATIONS

• Presented by Ridge Dorsey
• City of Boulder
• Pretreatment Program

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Format for this Presentation

• Discuss two general types of limits regulating
  industrial discharges.
• Provide an overview of Local Limits development
  process.
• How is industry information utilized.
• What future changes may effect industries.

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Government Disclaimer

• Im here to help you!
• The check is in the mail!
• Many programs/ many approaches. Speak with your
  local Pretreatment Coordinator.

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Federal limits vs Local limits

• Technology/BAT basis
• Level playing field, baseline for all
• End of process, after treatment

• Technical evaluation
• Protect POTW, biosolids, environment, workers
• End of pipe

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Why arent Fed. limits enough?

• Fed. Categorical Stds. do not address all
  contributed pollutants and are not applied to
  non-significant industrial users
• Categorical stds. may not adequately protect the
  POTW, Its collection system, biosolids, workers,
  or receiving water.

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Types of Local Limits

• Technically based numeric limitations for
  specific pollutants (Cd, Cr, Cu)
• General and specific prohibitions (temperature,
  ignitability, will not clog sewer)
• Best Management Practices
• or a blend of all the above applied to specific
  classes of discharges

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Legal Authority Cite

• 40 CFR 403.2 Objectives of the General
  Pretreatment Regulations are to prevent Pass
  Through, Interference, and improve opportunities
  to recycle and reclaim wastewater and sludges.
• 40 CFR 403.5(c) Each POTW shall continue to
  develop local limits as necessary and effectively
  enforce these limits.
• 40 CFR 403.5(d) Local Limits shall be
  Pretreatment Standards for the purposes of the
  CWA.

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Putting the Local into Local Limits Development

• Treatment plant design flow, treatment
  structures.
• Biosolids disposal practices
• NPDES Permit limits
• State and Federal Water Quality Standards

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Treatment Plant Design influences removal of
pollutants

• Trickling Filters
• Solids Contact / Activated Sludge
• Lagoons
• combined processes

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Biosolids must comply with disposal practice

• Composting
• Land Application
• Landfilling
• Incineration

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Receiving Stream Protection

• NPDES permit limits
• State and Federal Water Quality Standards

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EPA Region VIII Technically-Based Local Limits
Development Strategy

• THE LOCAL LIMITS BIBLE
• Elaborates on existing national guidance and
  clarifies what Region VIII will require, as a
  minimum, from POTWs developing revised or new
  technically-based local limits.

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Nuts and Bolts

• Review POTW influent pollutant scans
• Establish Pollutants of Concern (POCs)
• Establish sampling plan/program
• Evaluate data/ calculate removals

• Calculate limits based on most stringent criteria
• Allocate loadings
• Draft legal authority to implement/ local
  approval
• EPA Approval

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Pollutants of Concern - Review Priority Pollutant
Scan

• Required - As, Cd, Cr (t, VI, III), Cu, Pb, Hg,
  Mo, Ni, Se, Ag, Zn
• Listed in State WQ Stds for receiving water, or
  listed in NPDES permit
• Detected gt0.05 mg/l from 40 CFR 122 Appedix D,
  tables II or V
• Any other gt0.1 mg/l

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POCs continued

• Any if gt0.01 mg/l and has a Bio-concentration
  Factor greater than 300
• Conventional pollutant w/ influent loadings gt 70
  of plant capacity
• any identified through WET characterization
  studies suspected of toxicity
• Any other pollutant designated by POTW or
  Approval Authority

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Sampling Plan Goal

• Gather data necessary to determine actual loading
  from sources to the treatment plant.
• Data will be used to determine Maximum Allowable
  Headworks Loading (MAHL)

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Sampling Plan Locations

• POTW Influent / Effluent
• Sludge (Biosolids)
• Hauled Wastes
• Commercial Sources(non-SIUs)
• Domestic Only Sources
• Significant Industrial Users (SIUs)

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Compile Data/ Calculate limits

• EPA Region VIII spreadsheetplug and play
• Determines most stringent criteria, accounts for
  non-regulated loadings(domestic), applies safety
  factor
• Calculates MAHL, MAIL, and Uniform Concentration
  Limits !!!

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Decisions, Decisions, Decisions

• Which POCs actually need limits?
• Instantaneous Limits?Daily Limits? Monthly
  Limits?
• Uniform Concentration? Mass-based Limits?
• What about commercial contributions?

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Final Approval

• Local Approval first - citizen review, council
  approval
• EPA Approval - public notice

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Review of Adopted Limits

• Annual evaluations of MAHL
• NPDES permit changes
• Significant new discharges to POTW
• Unfavorable trends in pollutant loadings

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Proposed Changes by EPA Region VIII

• More focus on Commercial Loading Sources
• Provisions for adopting monthly limits to protect
  biosolids quality

• Requirements to establish local limits for
  Conventional Pollutants. (BOD, TSS, Ammonia)
• Advocating mass allocation of MAIL vs uniform
  concentration limits

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Questions?