Sewer Charge & Surcharge Provision Development, Implementation & Benefits

Transcription

1 Sewer Charge & Surcharge Provision Development, Implementation & Benefits 2013 Industrial Wastewater Conference Bethlehem, PA (October 4, 2013)

2 Human Waste Treatment History (1) Historically dilution in streams (Pits & discharge to streams) (2) 1887 : First biological treatment (Intermittent sand filter) in Medford, MA (3) 1899 : First Federal regulation of sewage Rivers & harbors Appropriations Refuse Act prohibiting discharge of solids to navigational waters without permit from US Army Corps of Engineers (4) 1901 First Trickling filter in Madison WI; 1909 Imhoff tank for solids settling; (5) 1914 liquid chlorine disinfection; (6) 1916 Activated sludge plant, St. Marcos, TX; 1940 s Secondary Treatment process to remove BOD (7) 1948 Federal Water Pollution Control Act for water quality surveys & construction of sewage collection and treatment plants Clean Water Act (8) 1960 Present : Treatment process advances include improved activated sludge processes, nutrient removals (ammonia, phosphorus, nitrates), oxic/anoxic systems, sequencing batch reactors, MBR, improved sludge digestion (high temp), etc.

3 Wastewater (Sewage) Treatment Plant & Treatment Capabilities (1) Design to treat human waste (domestic wastewater) (2) Design for specific parameters: BOD, TSS, NH3 (TKN) (Others: Phosphorus, Nitrate, Metals) (3) Treatment/Removal of Pollutants as a by product of biological treatment Biodegrade: O&G/TPHC, organics Release to air: Volatile organics Sludge Accumulation: Conventional pollutants, Metals, organics (untreated) (4) Untreated pollutants released to Surface Waters (submit to the permit) (5) Accumulated sludge Disposed offsite

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6 Discharges to Sanitary Sewer System (1) Sanitary discharge from households; (2) Stormwater (runoffs/overflows/combined sewers) (3) Groundwater inflow/infiltration (4) Commercial Discharge (Non domestic in nature) (Restaurants, laundries, carwash, garages, print/photo, NCCW, etc.) (5) Industrial Wastewater (Manufacturing and processing)

7 Protecting Wastewater Treatment Plant Design for domestic wastewater (human / household waste) Protect the treatment plant from any plant interference, inhibition, and bypass from non designed or incompatible discharge sources; Document all criteria applicable to plant and its operations: plant Design, process inhibition, process interference, sludge quality interference, NPDES (stream) discharge criteria, sludge disposal criteria, and worker safety Define what quality of non domestic wastewater could be acceptable to protect the plant. Development of plant specific local discharge limits Adopt and implement the local sewer discharge limitations

8 Typical Local Discharge Limitations BOD (2) TSS 250 (2) NH 3 N) 25 (2) TKN 40 (2) Oil/Grease 100 Temp. 65 Celsius ph S.U. Arsenic (T) 1.00 Beryllium(T) 0.10 Cadmium(T) 0.25 Chromium(T) 2.12 Copper (T) 2.88 Lead (T) 2.22 Mercury (T) 0.13 Molybdenum 0.16 Nickel (T) 3.09 Selenium (T) 0.20 Silver (T) 2.60 Zinc (T) 4.26 Cyanide (T) 1.04 Flash Point F(Min.) Total Toxic Organics (TTO) (3) (1) All units in mg/l, unless otherwise specified. All limitsasdailymaximum(composite samples), except for the instantaneous limits for the grab sample parameters. (2) A surcharge option for higher BOD 5, TSS, NH 3, and/or TKN limits may be available (see Section 6.4). (3) TTO limits may be imposed on a case by case basis. Discharge of toxic or hazardous substances is also prohibited under Section V. See Appendix B for the list of Total Toxic Organics. 6.4 SURCHARGE PROVISION FOR CONVENTIONAL POLLUTANTS 6.5 EXCEPTION & EXEMPTION PROVISIONS

9 Plant Available Treatment Capacities & Future Planning Review available excess capacities for: Flow, BOD, TSS, Ammonia and other plant design parameters; Address the service area (participating municipalities) future planning and growth; Assess available excess treatment capacities for the Designed pollutant parameters

10 Typical Plant Design and Compliance Criteria (A) (B) Typical biological WWTP design criteria are (Varies with plants): (1) BOD mg/l (Influent) 90% Removal rate (EPA minimum 85%) (2) TSS mg/l (Influent) 90% Removal rate (EPA minimum (3) NH mg/l (Influent) 90 95% Removal rate Typical WWTP Discharge/Effluent Limitations: (1) BOD mg/l (2) TSS mg/l (3) NH mg/l (Varies Summer/Winter limits) (4) Others: Phosphorus, Nitrates, Metals (Additional pollutants and discharge limitations and requirements based upon Federal and State permits)

11 Plant Design, Actual Performance & Capacity (A) If the WWTP is operated as designed, typically plant has excess capacities available to treat additional BOD5, TSS and NH3; likely due to Higher pollutant removal rates (Consistent below the effluent discharge quality requirements)better compliance Lower plant influent pollutant concentrations (In recent years some increases in pollutant concentrations due to the water conservation) Note: Higher available loading capacity does not mean the plant will operate under same conditions and at the same efficiency with higher influent pollutant loads. Need to check available air/supply and treatment capacities, retention time, effects on nitrification and bio treatments, higher sludge capacity, effect on other treatment units, etc. What to do with the excess available pollutant treatment capacities available at the plant?

12 Plant Design, Actual Performance & Capacity (Example) NJPDES POTW DESIGN 2011 POTW DATA (1) DAILY 2011 POTW LOADINGS (3) Calculated Daily Safety Available (5) PARAMETERS LIMIT CONCEN. LOADINGS Influent Effluent Removal LOADING Domestic Commercial Industrial Loading For Factor Daily Loading CAPACITY Loading Loading Loading Ind./Comm. 10%) For Ind./Comm. (mg/l) (mg/l) (lbs/day) (mg/l) (mg/l) (% ) (lbs/day) (lbs/day) (lbs/day) (lbs/day) (lbs/day) (lbs/day) (lbs/day) FLOW in MGD BOD5 (6) TSS (< 1.00) NH (< 1.00) TKN (7) PHOSPHORUS(8)

13 Sewer Surcharge Option Develop data base for at least 2 3 years and verify excess capacities are available; Hold about 20 % loadings as reserve to address any variations & unforeseen event; Calculate available excess loadings for the design pollutants (BOD5, TSS, NH3) These excess loadings could be made available to industrial and commercial dischargers for a surcharge payment for the actual loadings discharge over the domestic equivalent loadings. Implementation of the sewer surcharge provision is not mandatory, but quite common and recommended (Could be beneficial to POTW and industries)

14 Sample Primary Treatment Removal Rates Treatment Process Removal Rates Pollutant Month-Year Plant Plant Primary Primary Secondary Nitrification Plant Primary Secondary Nitrification Total FLOW Influent Influent Effluent Effluent Effluent Effluent Removal Removal Removal Removal BOD5 (in MGD) (in MG/L) (in MG/L) (in MG/L) (in MG/L) (in MG/L) (in MG/L) (in % ) (in % ) (in % ) (in % ) 1st Quarter 2/14/11-2/15/ < % 32.23% 21.62% 99.19% 2nd Quarter 4/11/11-4/12/ < % 19.49% 20.87% 99.42% 3rd Quarter 7/11/11-7/12/ < % 28.22% 15.67% 99.41% 4th Quarter 10/3/11-10/4/ < % 36.36% 17.63% 99.37% 2011 AVERAGE < % 29.08% 18.95% 99.35% 2011 LOADINGS =Lbs/day influent load Lbs/day load Removed= TSS (in MGD) (in MG/L) (in MG/L) (in MG/L) (in MG/L) (in MG/L) (in MG/L) (in % ) (in % ) (in % ) (in % ) 1st Quarter 2/14/11-2/15/ % 23.22% 18.05% 99.29% 2nd Quarter 4/11/11-4/12/ % 11.84% 10.74% 99.36% 3rd Quarter 7/11/11-7/12/ < % 15.51% 6.54% 99.83% 4th Quarter 10/3/11-10/4/ < % 26.04% 16.98% 99.79% 2011 AVERAGE % 19.15% 13.07% 99.57% 2011 LOADINGS =Lbs/day influent load Lbs/day load Removed= NH3-N (in MGD) (in MG/L) (in MG/L) (in MG/L) (in MG/L) (in MG/L) (in MG/L) (in % ) (in % ) (in % ) (in % ) 1st Quarter 2/14/11-2/15/ % 5.79% 91.85% 98.08% 2nd Quarter 4/11/11-4/12/ % 16.52% 82.26% 98.45% 3rd Quarter 7/11/11-7/12/ % 20.00% 73.22% 98.36% 4th Quarter 10/3/11-10/4/ % 15.33% 80.12% 98.67% 2011 AVERAGE % 14.41% 81.86% 98.39% 2011 LOADINGS =Lbs/day influent load Lbs/day load Removed= P(T) (in MGD) (in MG/L) (in MG/L) (in MG/L) (in MG/L) (in MG/L) (in MG/L) (in % ) (in % ) (in % ) (in % ) 1st Quarter 2/14/11-2/15/ % 4.85% 42.62% 71.97% 2nd Quarter 4/11/11-4/12/ % 4.88% 36.13% 67.92% 3rd Quarter 7/11/11-7/12/ % 17.85% 21.50% 67.51% 4th Quarter 10/3/11-10/4/ % 5.34% 40.25% 63.85% 2011 AVERAGE % 8.23% 35.12% 67.81% 2011 LOADINGS 73.5 =Lbs/day influent load Lbs/day load Removed= 49.8

15 Calculating Sewer Rates & Sewer Surcharge Rates (1) USEPA guidelines (early 1980 s) for User Charge & Related Revenue System Requirement for a POTW (2) More than one way to calculate rates, as long as it covers POTW costs and reasonably distribute them work related to corresponding pollutants removal (3) Basically calculating the treatment plant capital and operating costs and distributing the cost in the plant design parameters including: Flow (mostly sewer collection system operation) BOD5 TSS NH3 (TKN) Phosphorus & Others (if the plant is designed)

16 Sewer / User Rates (1) Applicable to all connections (Domestic and non Domestic discharges) (2) Includes Capital and operating costs, including debt obligations, O&M costs (3) Typically, based upon the discharge volume allocation (Equivalent Domestic Unit (EDU) and EDU multiple). (4) EDU could range from gallons/home/day (5) Some municipalities may have a fraction of EDU for lower size home ( e.g. 1 2 bedroom houses/apartments may have lower rates than 3 bedrooms)

17 Sewer Surcharge Rates Calculation (1) Allowed for only pollutants for which the plant is specifically designed (2) Sewer Surcharge Rates are in addition to the Sewer/User Charges (3) Sewer Surcharge Rates are calculated using only Plant O&M and Related Costs, including: All plant operation and maintenance costs, including electricity, chemicals, property maintenance, vehicles, sludge disposal cost, etc. Employee salaries and benefits Plant administration cost Regulatory and compliance cost Related engineering and legal cost DO NOT INCLUDED: Capital cost, debt service cost, IPP cost

18 Sewer Surcharge Rates Calculation (1) Breakdown of costs to specific Flow, BOD5, TSS, NH3 (TKN), etc. operations (2) Split O&M costs into specific process operations: Collection system (flow), primary treatment, biological/aeration treatment, nitrification, chemical treatment, disinfection, sludge operations, etc. (3) Estimate pollutant removal rate for each treatment unit operation (4) Split general cost items (administration, regulatory, legal, etc.) proportional to overall pollutant removal rates by each treatment unit. (5) Calculate surcharge rates ($$/pound of pollutant) for each pollutant: BOD5, TSS, NH3, etc.

19 HSA ADMINISTRATIVE COST Yearly Cost FLOW COST BOD5 COST TSS COST AMMONIA COST PHOSPHORUS COST Ref.# % Factor Cost % Factor Cost % Factor Cost % Factor Cost % Factor Cost 1100 Administration : Salaries & wages $198, % $42, % $62, % $74, % $13, % $5, Administration : Fringe benefits $98, % $20, % $31, % $36, % $6, % $2, Administration : Other $61, % $13, % $19, % $23, % $4, % $1, Administration : Insurance $9, % $2, % $3, % $3, % $ % $ Plant : Salaries & wages $1,540, % $328, % $486, % $575, % $104, % $44, Plant : Fringe benefits $776, % $165, % $245, % $290, % $52, % $22, Plant : Insurance $80, % $17, % $25, % $30, % $5, % $2, Plant : Electricity $330, % $ % $132, % $156, % $28, % $12, Plant : Sludge cost $162, % $ % $62, % $87, % $10, % $1, Plant : Fuel & water $167, % $ % $67, % $79, % $14, % $6, Plant : Maintenance supplies $78, % $ % $31, % $37, % $6, % $2, Plant : Maintenance services $149, % $ % $59, % $70, % $12, % $5, Plant : Equipment $20, % $ % $8, % $9, % $1, % $ Plant : Chemicals (Overall plant) $51, % $ % $20, % $24, % $4, % $1, Plant : Chemicals (Alum for P(T)) $50, % $0 0.00% $0 0.00% $0 0.00% $ % $50, Plant : Permits & Regulatory $20, % $ % $8, % $9, % $1, % $ Plant : Office supplies $13, % $ % $5, % $6, % $1, % $ Plant : Laboratory $122, % $ % $49, % $58, % $10, % $4, Plant : Safety $21, % $ % $8, % $10, % $1, % $ Professional Services (4) (7) $194, % $ % $78, % $92, % $16, % $7, Vehicle expense (5) $30, % $24, % $2, % $2, % $1, % $204 $0 $0 $0 $0 $ Township Reimbursement $64, % $64,015 $0 $0 $0 $ Administration : Fiscal Agent $ % $0 $0 $0 $0 $ Collection System $263, % $263,600 $0 $0 $0 $ Industrial Pretreatment Program (7) $210,600 $0 $0 $0 $0 $ Debt Service $225, % $225,000 $0 $0 $0 $ Plant Expansion $500, % $500,000 $0 $0 $0 $0 Total Other Admin. Costs $5,439,786 $1,666,613 $1,408,548 $1,679,429 $300,728 $173,852

20 Sewer Charges & Surcharge Allocating Excess capacity for Payment of Surcharge (1) Calculate overall plant excess capacities for each BOD5, TSS, NH3, etc. (2) Reserve about 20% of excess pollutant capacities (3) Allocate excess Available capacities to industrial/commercial dischargers (typically on a first come first serve basis) (4) Establish upper cutoff discharge limits (Concentrations and/or loadings) for each User, as necessary (5) Document, review and update Available excess capacities each year. (6) Recommended to update the sewer surcharge rates ($$/lb) every two years.

21 Sewer Charges & Surcharge Assessing Individual Surcharge Cost Equation #1: Rx = Ex (8.34) (365) (QT) (CT) Equation #2: S ind. = (Rx) (Q ind ) (C ind C x,l ) (8.34) Rx = Surcharge rate for parameter (x) in dollars per pound. Ex = Annual O&M cost of the POTW associated with treatment of parameter(s) in dollars per year. QT = Average daily influent flow to the wastewater treatment plant (POTW) in million gallons per day. CT = Average daily influent concentration of parameter (x) to the WTP in mg/l. X = Pollutant parameters e.g. BOD5, TSS, NH3, TKN, etc. (8.34) = Conversion factor. Sind. = Monthly sewer surcharge for Users/dischargers in dollars, which is summation of sewer surcharges for all applicable pollutant parameters. Q ind = Total monthly discharge from the User in millions of gallons. C ind = Average discharge concentration of pollutant parameter (x) in milligrams per liter of the Users discharge C x,l = Discharge (domestic Equivalent) concentration for the pollutant parameter (x) in mg/l.

22 Sewer Charges & Surcharge Case History (1) Beverage Manufacturer #1 (High BOD loadings) Typical range: Flow 70,000 gpd, BOD5 1,800 mg/l, TSS 600 mg/l Large WWTP with available excess loadings Issued a discharge permit with a surcharge provision (no cutoff limits) Monthly surcharge fees for BOD5 and TSS in the range of $14,000 (2) Beverage Manufacturer #2 (High BOD loadings) Typical range: Flow 350,000 gpd, BOD mg/l, TSS 1000 mg/l Medium WWTP with limited available loadings Issued a discharge permit with a surcharge provision (with cutoff limits) Monthly surcharge fees for BOD5 and TSS in the range of $125,000 $150,000

23 Sewer Charges & Surcharge Case History (Continued) (3) Food Processer #1 (High BOD & TSS loadings) Typical range: Flow 120,000 gpd, BOD5 2,200 mg/l, TSS 500 mg/l Large WWTP with available excess loadings Issued a discharge permit with a surcharge provision (no cutoff limits) Monthly surcharge fees for BOD5 and TSS in the range of $40,000 (4) Food Processer #2 (High BOD & TSS loadings) Typical range: Flow 250,000 gpd, BOD5 1,800 mg/l, TSS 600 mg/l Large WWTP with available excess loadings Issued a discharge permit with a surcharge provision (no cutoff limits) Monthly surcharge fees for BOD5 and TSS in the range of $60,000 $75,000

24 Sewer Charges & Surcharge Case History (Continued) (5) Cheese Processer #1 (High BOD & TSS loadings) Typical range: Flow 15,000 gpd, BOD5 900 mg/l, TSS 600 mg/l Large WWTP with available excess loadings Issued a discharge permit with a surcharge provision (no cutoff limits) Monthly surcharge fees for BOD5 and TSS in the range of $2,000 (6) Small Slaughter House (High BOD, TSS & NH3 loadings) Typical range: Flow 7,000 gpd, BOD5 8,000 mg/l, TSS 1,200 mg/l, NH3 100 mg/l Small WWTP with limited available excess loadings Issued a discharge permit with a surcharge provision (With cutoff limits) Monthly surcharge fees for BOD5 and TSS in the range of $20,000

25 Sewer Charges & Surcharge Case History (Continued) (7) Restaurant / Catering #1 (High BOD, TSS, NH3 loadings) Typical range: Flow 5,000 gpd, BOD5 1,500 mg/l, TSS 1,200 mg/l, NH3 100 mg/l Small WWTP with limited available excess loadings Issued a discharge permit with a surcharge provision (with cutoff limits) Monthly surcharge fees for BOD5, TSS & NH3 in the range of $4,000/month (8) Industrial Manufacturer #1 (High BOD, COD & TSS loadings) Typical range: Flow 60,000 gpd, high variable BOD5, COD, TSS Medium WWTP (will not accept excess loading due chemical manufacturing) Permit with no surcharge provision (BOD5 350, COD 500, TSS 350 limits) Waste stream segregation (concentrates disposed offsite) Installed pretreatment system with equalization, DAF, biological (aeration) treatment, sludge collection (and offsite disposal)

26 Sewer Charges & Surcharge Surcharge Option or Pretreatment (Pay or Treat) (1) Typically industrial and commercial users are not in business of waste treatment (2) Pretreatment will most likely require biological treatment system (aerobic / anaerobic) (3) Pretreatment design, construction & operation cost varies with flow and load (4) Check available space (5) Check other regulatory compliance requirements (Construction permits, sludge disposal issues, air or other permits, safety) (6) Evaluate costs pretreatment and surcharge rates & decide.

27 Sewer Charges & Surcharge THANK YOU Contact Information: Richard Lulla, P.E. Senior Associate Hatch Mott MacDonald 111 South Wood Avenue Iselin, New Jersey