1. New Approaches to Developing Local Limits Industrial & Hazardous Waste Committee Meeting July 18, 2001 by Richard W. von Langen, P.E. New Approaches to Developing Local Limits

2. New Approaches to Developing Local Limits 2 I&HW Committee July 18, 2001 Sampling Data 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

3. New Approaches to Developing Local Limits 3 I&HW Committee July 18, 2001 Characterizing the Waste and How Low Can You Go ? 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

4. New Approaches to Developing Local Limits 4 I&HW Committee July 18, 2001 Now… What do I do with the Data? 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

5. New Approaches to Developing Local Limits 5 I&HW Committee July 18, 2001 Limiting Criteria 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

6. New Approaches to Developing Local Limits 6 I&HW Committee July 18, 2001 Mass Balances Headworks data are the fulcrum point for mass balances Industrial Waste Residential Commercial Effluent Sludge Headworks

7. New Approaches to Developing Local Limits 7 I&HW Committee July 18, 2001 Headworks Mass Balance IW + 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%

8. New Approaches to Developing Local Limits 8 I&HW Committee July 18, 2001 Plant Mass Balance Sludge Sludge Treatment Headworks Secondary Treatment Primary Treatment Disinfection Effluent Chemical Addition Consumption Different disposal options No prim/sec sludge data Return flows NDs

9. New Approaches to Developing Local Limits 9 I&HW Committee July 18, 2001 American Canyon WWTP Flow Diagram Industrial Flow Treatment Train 1 Surface Water Discharge* Chlorine Disinfection UV Disinfection Reuse as Recycled Water Domestic/ Commercial Flow (Winter) Sludge Holding Basin Landfill Land Application Dewatered Sludge Sludge Treatment Trains 2, 3, 4 * Instantaneous concentration limits and rolling 12-month mass limits

10. New Approaches to Developing Local Limits 10 I&HW Committee July 18, 2001 VCWD WWTP Sludge Sludge Treatment Headworks Secondary Treatment Primary Treatment Percolation Ponds Discharge Tertiary Treatment Recycle

11. New Approaches to Developing Local Limits 11 I&HW Committee July 18, 2001 Example - Aluminum 1.8 X 2.4 = 36# 50# 39# E - 6# S - 33# R - 2.65 x 2.22 = 49# I - 0.82 x 0.18 = 1# C- ?

12. New Approaches to Developing Local Limits 12 I&HW Committee July 18, 2001 Raw Data - Aluminum (mg/L) Residential Avg – 2.66SD – 1.01 % SD – 38 Med – 2.4

13. New Approaches to Developing Local Limits 13 I&HW Committee July 18, 2001 Raw Data - Aluminum (mg/L) Headworks

14. New Approaches to Developing Local Limits 14 I&HW Committee July 18, 2001 Aluminum Local Limit 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

15. New Approaches to Developing Local Limits 15 I&HW Committee July 18, 2001 Example - Cadmium R - ND C - ? I - 0.00154# E - ND S - 0.0021# ND

16. New Approaches to Developing Local Limits 16 I&HW Committee July 18, 2001 Raw Data - Cadmium mg/L Industrial Contribution

17. New Approaches to Developing Local Limits 17 I&HW Committee July 18, 2001 Cadmium Local Limit

18. New Approaches to Developing Local Limits 18 I&HW Committee July 18, 2001 Example - Silver R - <DL mg/L C - ? I - 0.00054# E - ND mg/L S - 0.013# Headworks <DL

19. New Approaches to Developing Local Limits 19 I&HW Committee July 18, 2001 Limiting Criteria for 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?

20. New Approaches to Developing Local Limits 20 I&HW Committee July 18, 2001 Mass Balance - Chloride mg/L R - 44.6 C - ? I - 115 Cl 2 E - 49 S - ? Headworks 44 mg/L

21. New Approaches to Developing Local Limits 21 I&HW Committee July 18, 2001 TDS Local Limits Limiting 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

22. New Approaches to Developing Local Limits 22 I&HW Committee July 18, 2001 Sensitivity Analysis 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 Take a Global Perspective