Cranston Sewer Use Ordinance

Transcription

1 Cranston Sewer Use Ordinance Proposed Revisions to Local Discharge Limits August 27, 2012 Presented by Veolia Water Daniel Gorka

2 Local Limits Revisions - Background The Cranston Water Pollution Control Facility (WPCF) treats domestic and industrial wastewater collected from the Cranston sewer collection system The WPCF is regulated under the EPA Clean Water Act and the State of Rhode Island under the RI Pollutant Discharge Elimination System (RIPDES) EPA delegates its authority to the RI DEM to manage the discharge from Publically Owned Treatment Works (POTW) in the State of RI. The WPCF is a POTW. RI DEM delegates, in part, its authority to the POTW s with respect to regulating industrial wastewaters discharged to each POTW

3 Local Limits Revisions - Background As part of RI DEM s delegation, each POTW is required, from time to time, to revise the limits of EPA defined Pollutants of Concern (POC) that are allowed to be discharged by non-domestic sewer users as well as any other pollutants that may be a local concern to the POTW. The POTWs are required to adhere to EPA guidelines when determining the local limits.

4 Cranston Water Pollution Control Facility In October 2008, RIDEM issued a new discharge permit revising a number of limits on pollutants discharged by the Cranston POTW Several new pollutants were also added to the permit accompanied by discharge limits The Cranston POTW was not able to meet a number of revised and new pollutant limits due to the treatment capacity of the POTW Additionally, the new permit required the City to evaluate and, if necessary, modify its existing local limits for non-domestic users.

5 Cranston Water Pollution Control Facility The City and RIDEM entered into a Consent Agreement in November 2009 that provides a schedule for the City to meet the new limits by taking measures that include: Upgrading the WPCF to increase its treatment capacity Establishing new local limits for non-domestic sewer users that may help reduce loadings to the WPCF.

6 Evaluation of Local Limits and POC s EPA guidelines include a list of pollutants of concern (POC) that are required to be evaluated to determine if the POTW should establish Local Limits for each pollutant that are applicable to non-domestic users. Cranston s Sewer Use Ordinance already has limits in effect for most of the EPA POC s. However, due to the new RIDPES Discharge Permit for the WPCF, some of these POC s limits needed to be revised. There were also several additional POC s added to the Local Limits as a result of the WPCF s new RIPDES permit.

7 Additional Pollutants of Concern for the WPCF Pollutant EPA POC (Original) EPA POC (2004) Total Nitrogen (NH3) Arsenic Biochemical Oxygen Demand (BOD) Cadmium Chromium Copper Cyanide Lead Mercury Molybdenum Nickel Selenium Silver Suspended Solids, Total Zinc

8 Additional Pollutants of Concern Pollutant Carbonaceous Biochemical Oxygen Demand (CBOD5) Nitrogen, Total Oil & Grease ph Phosphorus, Total Sulfate Tetrachloroethylene Volatile Compounds, Organic Volatile Compounds, Semi-Organic Additional Concerns WPCF Capacity / New RIPDES Permit Limits WPCF Capacity / New RIPDES Permit Limits Fouling / Clogging of Sewer System Corrosion of Sewer System WPCF Capacity / New RIPDES Permit Limits Potential Odor Contribution Removed from RIPDES Toxicity to WPCF Toxicity to WPCF

9 Evaluation of POC s Identified POC s were evaluated based on the WPCF s current discharge limits and other factors that could affect the WPCF s ability to provide overall treatment. The first step was to determine the maximum pollutant loading from each POC based on the WPCF s treatment capacity with respect to each POC and overall WPCF performance. The maximum allowable loading to the WPCF is determined on a mass basis. The next step is to determine domestic loading for each POC.

10 Evaluation of POC s The Domestic Loading is then subtracted from the Maximum Allowable Loading to the WPCF The difference is then allocated towards nondomestic users (industries and commercial businesses): NDL = MAL - DL NDL = Available Non-Domestic Loading MAL = Maximum Allowable Loading to the WPCF DL = Domestic Loading

11 Determination of Local Limits Based on the WPCF s Maximum Allowable Loading and Domestic Loading, there were some cases where the available loading for Non-Domestic Users was less than the actual loadings. This was the case for the following POC s: CBOD 5 Total Nitrogen Arsenic For the above POC s, the allocated Non-Domestic Loading was less than collective loadings currently discharged by the Non-Domestic Users

12 Determination of Local Limits Limits were determined based on how the available POC loadings were allocated amongst non-domestic users. In the case of Total Nitrogen and Arsenic, allocations were made by limiting the concentration of POC discharged by Non-Domestic users. The concentration was uniform and the loading contributed by each Non- Domestic User was proportional to the volumetric flow of sewer discharge made be each user. In the case of CBOD 5, allocations were made using mass-loading limits instead of concentration limits based. Several mass-loading limits were established and applied to different groups of users.

13 Recommended Changes to Local Limits (Concentration-Based) Parameter Current Limit Recommended Limit Arsenic, Total Not Detectable mg/l Beryllium, Total Not Detectable eliminate this parameter from SUO Cadmium, Total 0.04 mg/l mg/l Chromium, Total 0.40 mg/l 2.6 mg/l Copper, Total 1.00 mg/l 0.57 mg/l Lead, Total 0.30 mg/l 0.30 mg/l Mercury, Total Not Detectable mg/l Nickel, Total 0.70 mg/l 0.77 mg/l Silver, Total 0.10 mg/l 0.12 mg/l Zinc, Total 1.00 mg/l 0.71 mg/l Cyanide, Total 0.30 mg/l 0.26 mg/l PCBs, Total < mg/l < mg/l Total Toxic Organics 2.13 mg/l 2.13 mg/l Total Nitrogen (Ammonia-N, Nitrite-N, Nitrate-N & Organic-N) no prior limit 50 mg/l Total Phosphorus no prior limit 7.3 mg/l ph 5.5 to 9.5 standard units 5.5 to 10.5 standard units 100 mg/l (Animal / Vegetable Origin) 100 mg/l (Animal / Vegetable Origin) Oil & Grease 25 mg/l (Oil Origin) 25 mg/l (Oil Origin)

14 Recommended Changes to Local Limits (Mass-Based Limits) Parameter 5-Day Carbonaceous Biochemical Oxygen Demand (CBOD 5 ) Current SUO Limit No Prior limit Recommended SUO Limit 1198 lbs/day lbs/day 2 50 lbs/day 3 25 lbs/day 4 (average monthly) 1 Applicable to Significant Industrial Users (SIU) in SIC categories of 7213, 7218, 2086, and Applicable to SIUs in all food processing industries, but not applicable to SIC code Applicable to SIUs having SIC category of Applicable to SIUs having SICs other than 7213, 7218, 2086, 4953, 4911 and not in a food processing industry.

15 SIC Code SIC Description Applicable CBOD Limit, Lbs/day Affected businesses 7213 Linen Supply 1,198 Falvey Linen 7218 Industrial Launderers 1,198 Falvey Linen Bottled & Canned Soft Drinks, Carbonated 2086 Beverages 1,198 The Pepsi Bottling Group 4953 Refuse Systems 1,198 RIRRC All SIU Food processing except SIC Eastland Foods Electric Services 4911 Industry 50 Entegy All SIU's not listed above 25 All other Significant IU's