Duyen Tran

OMI, Inc.

The “Bible”

EPA Guidance Manual on the Development and

Implementation of Local Discharge Limitations Under

the Pretreatment Program

EPA 833-R-04-002A

July 2004

7-steps process

• Preliminary Data Collection

• Identify Pollutants of Concern

• Sampling Plan

• Data Collection & Evaluation

• Calculation

• Technical Review

• TBLL Submission

Preliminary Data Collection

• Receiving stream designation• Water Quality Standards for the designated

receiving stream• Most recent priority pollutant scans on plant

influent (include analyses of additional pollutants specified in State Water Quality Standards)

Identify Pollutants of Concern (POC)

• Pollutants with concentration greater than 0.1 mg/l in the influent scan, adjust for inflow/infiltration if the plant has I/I problem

• Pollutants associated with historical plant problems

• Fifteen EPA’s POCs: Cd, Cr, Cu, Pb, Ni, Zn, As, CN, Ag, Hg, Mo, Se, BOD, TSS, Ammonia

Sampling Plan

• Review historical data on pollutants of concern for: influent, effluent, primary effluent, sludge, industrial effluent, inhibition data, background (domestic & commercial)

• Reject data that is anomaly• Reject data that does not meet laboratory

QA/QC or required MDLs

Sampling Plan (cont’d)

• In lieu of at least 6 months of historical data, collect at least 6 consecutive days of samples for influent, effluent, and background

• Consider plant retention time when collecting new influent and effluent data

• In all cases, obtain the most representative collection of data for TBLL calculation

Data Collection & Evaluation

• NPDES Permit• State WQS• 503 Sludge Criteria• Receiving Stream,

7Q10 or 7Q2• Plant diagram and

description of plant processes

• POTW Flow• Digester Flow• Industrial Flows• Background Flow

(Domestic + Commerical)

Data Collection & Evaluation

• Review analytical data for:– Chain of custody– Laboratory QA/QC– MDLs

• Reject data that appears to be anomaly or does not meet the above criteria

• Document the data evaluation process

Calculation

• Plant Removal Efficiency, %• Allowable Headworks Loadings• Background (Domestic) Loadings• Derive Maximum Allowable Headworks Loadings

(MAHL)• Maximum Allowable Industrial Loadings (MAIL)

Allowable Headworks Loadings (AHL)

Calculate AHL for:

• Water Quality Standards

• NPDES Permit

• Process Inhibition/Operational Problems

• Sludge Disposal Criteria

Pollutant AHL-NPDES AHL-WQS AHL-INH AHL-503 MAHL(lbs/d) (lbs/d) (lbs/d) (lbs/d) (lbs/d)

BOD 18129 18129TSS 44120 44120

Ammonia 650 649.80Phosphorus 164 164.19Oil/Grease 2548 2548

Arsenic 22.62 7.51 2.10 2.10Cadmium 0.35 88.31 2.18 0.35Chromium 64.15 102.82 81.98 64.15

Copper 7.21 96.23 46.12 7.21Cyanide 0.62 10.28 0.62

Lead 1.13 8.34 10.76 1.13Mercury 0.0029 17.46 0.87 0.003Nickel 16.52 87.28 59.18 16.52Silver 23.46 23.46Zinc 12.88 19.93 30.85 161.62 12.88

COMPARISON OF ALLOWABLE HEADWORKS LOADINGS

Maximum Allowable Industrial Loadings,

MAIL

MAIL = MAHL - (Background + Safety Factor)

Allowable Actual RequiredPollutant MAHL BKG (*) BKG IND Loadings IND Loadings IND Removal

(lbs/d) mg/l lbs/d (lbs/d) (lbs/d) (lbs/d)

Arsenic 2.10 0.015 1.0781 1.0227 0.0904 0.0Cadmium 0.35 0.000 0.0000 0.3488 0.0103 0.0Chromium 64.15 0.005 0.3594 63.7928 0.0550 0.0Copper 7.21 0.032 2.2999 4.9052 0.1398 0.0Cyanide 0.62 0.000 0.0000 0.6202 0.0053 0.0

Lead 1.13 0.0125 0.8984 0.2365 0.1393 0.0Mercury 0.00 0.00000 0.0000 0.0029 0.0001 0.0Nickel 16.52 0.010 0.7187 15.8025 0.0631 0.0Silver 23.46 0.005 0.3594 23.0969 0.0319 0.0Zinc 12.88 0.100 7.1872 5.6883 0.3069 0.0

BKG, lbs/d = Background Loadings = BKG conc.*Qb*8.34Qb = Background flow, MGD = 8.62

Comparison of MAHL to Actual Industrial Loadings w/o Safety Factor

Allocation

• Uniform Concentration

• Industrial Contributory Flow

• Mass Proportion Method

• Selected Industrial Reduction Method

Applications of Local Limits

• Industrial Discharge Permit Limits Calculation

• New Discharge Permit Consideration

• Plant Loadings Assessment

Technical Review

• Technical Support Staff

• City Engineers

• City Council

TBLL Submission

• Use State guidelines and checklist on program modification and submittal

• Prepare a professional certification

• Incorporate the new technically based local limits to the sewer use ordinance (SUO)

• Submit three copies of the TBLL study and revised SUO to the State

Resources

• EPA Guidance Manual on the Development and Implementation of Local Discharge Limitations Under the Pretreatment Program

• EPA Supplemental Manual

• EPA Region VI TBLL Guidelines

Duyen Tran, Project Manager

OMI, Inc.

City of Fayetteville WWTP

1400 N. Fox Hunter Road

Fayetteville, AR 72701

duyen.tran@omiinc.com

(479) 443-3292