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New Approaches to Developing Local Limits. New Approaches to Developing Local Limits. Industrial & Hazardous Waste Committee Meeting July 18, 2001 by Richard W. von Langen, P.E. Where? What? When?. Residential, Commercial, Industrial, Treatment Plant, Collection System
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New Approaches to Developing Local Limits New Approaches to Developing Local Limits Industrial & Hazardous Waste Committee Meeting July 18, 2001 by Richard W. von Langen, P.E.
Where? What? When? Residential, Commercial, Industrial, Treatment Plant, Collection System POC, Conservative, Non-Conservative, O&G, VOC, TDS, pH 1-2 Weeks, Monthly, Quarterly, Weekends, Wet Season, Dry Season Sampling Data
Metals CN, O&G, VOC BOD, TSS Representative Sampling Liquids Versus Sludge Ag, As, Cd, Cr, Cu, Hg, Ni, Pb, Zn Grab Samples? CN in residential WW ? Flow Proportional, Process Water Meters Characterizing the Waste andHow Low Can You Go ?
Mass Balances The “< MDL” Dilemma Variable When There Isn’t Enough? Collection System, Headworks, Plant Should the value be used? Assign it a O or =, 50%, or 2/3 of the MDL? O to > Avg + 2 SD; SD > 20%, NDs Less than 5 (10, 21?) data points Now… What do I do with the Data?
Collection System & Primary Treatment Worker Health & Safety Biological Treatment Inhibition Effluent Limit Sludge Disposal Air Emissions Physical Inhibition or Corrosion Airborne, pH related EPA Guidance, Plant Data? Stream, CTR, Ocean Discharge Limit, Title 22, No Limit 503, Fed HW, State-TTLC, STLC Odor, VOC Limiting Criteria
Mass BalancesHeadworks data are the fulcrum point for mass balances Industrial Waste Residential Commercial Effluent Sludge Headworks
Headworks Mass BalanceIW + RES + COM = Headworks • Effect of Collection System Operations • Lots of NDs • One or Two NDs • No Commercial Samples • Headworks Data Versus Plant Removal • EPA-Within 10-15%
Plant Mass Balance Headworks Primary Treatment Secondary Treatment Disinfection Effluent Sludge Treatment • Chemical Addition • Consumption • Different disposal options • No prim/sec sludge data • Return flows • NDs Sludge
American Canyon WWTP Flow Diagram Treatment Train 1 UV Disinfection Industrial Flow Surface Water Discharge* Sludge (Winter) Domestic/ Commercial Flow Reuse as Recycled Water Treatment Trains 2, 3, 4 Chlorine Disinfection Sludge Dewatered Sludge Land Application Sludge Holding Basin Landfill * Instantaneous concentration limits and rolling 12-month mass limits
VCWD WWTP Headworks Primary Treatment Secondary Treatment Percolation Ponds Tertiary Treatment Recycle Sludge Treatment Discharge Sludge
Example - Aluminum E - 6# S - 33# R - 2.65 x 2.22 = 49# I - 0.82 x 0.18 = 1# C- ? 39# 50# 1.8 X 2.4 =36#
Raw Data - Aluminum (mg/L) Residential Avg – 2.66 SD – 1.01 % SD – 38 Med – 2.4
WDR POTW Flow POTW % Removal MAHL Existing Influent Uncontrolled Influent MAIHL Uniform IU Conc. Without Safety Factor 1.0 mg/L 2.4 MGD 84 128 lb/day 36-50 lbs/day 35-49 lbs/day 93-79 lbs/day 63-53 mg/L Aluminum Local Limit
Example - Cadmium R - ND C - ? I - 0.00154# E - ND S - 0.0021# ND
R - <DL mg/L C - ? I - 0.00054# E - ND mg/L S - 0.013# Headworks <DL Example - Silver
Process Inhibition Pass Through Sludge Criteria No EPA Criteria CTR?, Effluent Limit, WDR, Title 22 No 503 Requirement, Federal HW? California HW - TTLC, STLC? Limiting Criteria for Silver
Mass Balance - Chloride mg/L R - 44.6 C - ? I - 115 Cl2 E - 49 S - ? Headworks 44 mg/L
TDS Local LimitsLimiting Criteria - Water Source + 400 mg/L Approach: • Compute controlled and uncontrolled concentrations of TDS • Subtract (average, highest, lowest?) source water concentration • Compute MAHL using 400 mg/L and WWTP influent flow • Subtract uncontrolled mass using (average, highest, lowest, upper quartile, average + 1 SD) uncontrolled sources concentration • Subtract safety factor • Allocate MAIHL to all Industrial Users
NDs Variable Data Expansion Factor Allocation Method TDS Calculate LL at different ND values; adjust headworks concentration to match mass balance Eliminate outliers; use geometric mean or median to calculate LL Vary; compare to Residential, Commercial, and Industrial Waste contributions Total versus contributory IU flows Vary concentrations of source water, and uncontrolled sources Sensitivity Analysis Take a Global Perspective