RE: Annual Report 2016 Wardsville Wastewater Treatment Plant and Collection System

Transcription

1 14 th, 217 Tom Clubb 3232 White Oak Road, 3 rd Floor London ON N6E 1L8 Attention: Mr. Clubb RE: Annual Report 216 Wardsville Wastewater Treatment Plant and Collection System The Ontario Clean Water Agency is the Operating Authority for the Wardsville Wastewater Treatment Plant and Collection System on behalf of Municipality of Southwest Middlesex. The system is currently operated under Environmental Compliance Approval JKFE and 468-4FNLG6. Please find attached the 216 Annual Report for the Wardsville Wastewater Treatment Plant and Collection system. Feel free to contact me should you require any additional information regarding the report. I can be reached at Sincerely, Cindy Sigurdson Safety, Process and Compliance Manager, Ontario Clean Water Agency c.c. Tara Clayton, Municipality of Southwest Middlesex Elizabeth Cummings, Municipality of Southwest Middlesex Dale LeBritton, Ontario Clean Water Agency Stephen Dunn, Ministry of the Environment and Climate Change

2 MUNICIPALITY OF SOUTHWEST MIDDLESEX WARDSVILLE WASTEWATER TREATMENT PLANT AND COLLECTION SYSTEM 216 ANNUAL REPORT 1 to 31, 216 Environmental Compliance Approval JKFE 468-4FNLG6 Prepared by:

3 Table of Contents Section 1: Overview... 1 Section 2: Monitoring Data... 2 Section 3: Operating Problems and Corrective Actions Section 4: Maintenance Section 5: Quality Assurance Section 6: Calibration and Maintenance Section 7: Quality Section 8: Biosolids Management Section 9: Community Complaints Section 1: Bypass, Spills, and Abnormal Discharges Section 11: Summary Appendix A: Analytical Data

4 Section 1: Overview The Wastewater Treatment Plant and the Main Pumping Station were operated under the Environmental Compliance Approval JKFE, issued 27, 21. The other two pumping stations and the SBS collection system are on a separate Environmental Compliance Approval, 468-4FNLG6 issued 24, 2. Collection System The collection system consists of a Small Bore Sewer (SBS) system rather than a conventional sanitary sewer system. This system uses on-site SBS clarifiers for each individual lot, consisting of approximately 145 residential and 6 commercial/institutional properties. The SBS clarifiers overflow into the SBS sewer system to one of the two pumping stations. The pumping stations then direct the flow to the main pumping station where the forcemain pumps the influent to the Wastewater Treatment Plant. The SBS system is maintained by the Municipality of Southwest Middlesex, while OCWA operates the pump stations. Plant Description Sewage enters a splitter box equipped with a manually cleaned bar screen. The splitter box is designed for a peak flow of 11m 3 /day and includes two sluice gates to divide and direct the sewage into two parallel extended aeration treatment trains. Soda ash is added at the splitter box by the chemical feed system for alkalinity adjustment. Each individual extended aeration treatment train includes the following components: i) A 9m 4.5m 4.5m extended aeration tank sized for 24 hours detention time assuming an average daily flow of 15m 3 /day. The tank is designed to achieve dissolved oxygen (DO) concentration of 2mg/L. ii) iii) A secondary clarifier tank sized for a peak hydraulic loading of 55m 3 /day together with stilling well, baffles and air lift sludge pump that directs sludge into the on-site sludge management facilities. A continuous backwash down flow granular sand filter sized for a peak hydraulic loading rate of 55m 3 /day. Approximately 6 to 8% of the effluent that flows through the filter is backwashed. The effluent from each treatment train s sand filter is combined and directed into a 1m 5.6m 4.5m post-aeration tank designed to achieve a DO concentration of at least 5mg/L in the effluent. Following the aeration, the effluent is directed to an in-ground chamber housing a UV disinfection system designed for a peak hydraulic flow of 11m 3 /day. The outfall is located less than 5m from the sewage works and discharges to the Thames River. Phosphorus and solids removal is achieved by the addition of aluminum sulphate (alum) from two metering pumps that inject into the aeration tanks. The alum is stored in a 34L storage Page 1 of 14

5 tank. Carrier water was added to the alum system to help prevent blockages and freezing of the alum lines. The sludge management system consists of an aerobic digestion tank sized to achieve a 45 day sludge age in combination with the aeration tanks. The sludge is then transferred to the aerated sludge holding tank (25m 3 ) sized to hold six months of sludge before it is hauled to another facility for further processing. Two blowers were added to the system, dedicated to providing air to the holding tanks. Section 2: Monitoring Data Sampling and Testing All samples are collected and tested as per the requirements of the Environmental Compliance Approval. Raw sewage is sampled twice per month and tested for BOD 5, total suspended solids, total phosphorus, and total Kjeldahl nitrogen. The raw samples are collected as grab samples. Final effluent is sampled weekly and tested for cbod 5, total suspended solids, total phosphorus, and total (ammonia +ammonium) nitrogen. Samples are collected using an automatic composite sampler and collected over a twenty-four hour period. As well, a weekly grab sample for E. coli is obtained. In house grab samples are collected and tested for ph, dissolved oxygen, and temperature. In-house tests are conducted on a weekly basis on the final effluent, raw influent and the mixed liquor to confirm plant performance and to make any operational adjustments. Extra samples were collected on the raw sewage and tested for total (ammonia +ammonium) nitrogen and alkalinity. Alkalinity tests are completed on the final effluent for better operational control of the soda ash dosing. In 215, all chemical and microbiological sample analyses were conducted by SGS Lakefield Research. Temperature, ph and dissolved oxygen were conducted by the operators at the treatment plant. The receiving stream temperature is monitored at the Thames River. Raw Sewage Quality Table 1 represents the raw sewage (influent) quality compared to the values to which the plant was designed to treat. See Appendix A for more detailed analytical data. The annual averages were below the design the criteria for all parameters except TKN. Despite the higher concentration of TKN the plant was able to meet compliance limits in the effluent for Total Ammonia Nitrogen. Page 2 of 14

6 Table 1. Raw sewage annual average concentrations compared to the treatment plants design concentrations. BOD5 TKN TP TSS Annual Average Design Objective # Months Design Objective Exceeded 2/12 1/12 4/12 /12 The annual average raw sewage BOD 5 concentration to the plant was 122mg/L with a maximum concentration of 166mg/L. The average concentration of BOD 5 has decreased 15.3% from 215, refer to Chart 1. The average BOD 5 loading to the plant was 9.53kg/d for 216. There were two months in 216 where the monthly average raw concentration was above the design criteria. Chart 1. Average monthly raw sewage BOD 5 concentrations in 216 compared to 215 concentrations Raw BOD5 216 Raw BOD5 Design Criteria Jan Feb Mar Apr Jun Jul Aug Sep Oct Nov Dec Annual Avg. Page 3 of 14

7 The annual average raw sewage suspended solids (TSS) concentration to the plant was 31.5mg/L, which is a 2.6% increase from 215 (refer to Chart 2). This corresponds to an average TSS loading to the plant of 2.46kg/day in 216. Chart 2. Average monthly raw sewage TSS concentrations in 216 compared to 215 concentrations Raw SS 216 Raw SS Design Criteria Jan Feb Mar Apr Jun Jul Aug Sep Oct Nov Dec Annual Avg. The annual average raw sewage nitrogen concentration (as represented by TKN) to the plant was 49.6mg/L with a loading of 3.88kg/d. This is a decrease of 9.5% from 215 annual average concentration, refer to Chart 3. There were ten months in 216 the raw concentration of TKN was above the design concentration of 4mg/L, which also resulted in the annual average above the design concentration. Page 4 of 14

8 Chart 3. Average monthly raw sewage TKN concentrations in 216 compared to 215 concentrations Jan Feb Mar Apr Jun Jul Aug Sep Oct Nov Dec Annual Avg. 215 Raw TKN 216 Raw TKN Design Criteria The annual average raw sewage total phosphorous (TP) to the plant was 6.89mg/L with a loading of.54kg/day. This represents a 6.4% decrease from 215 annual average concentrations, refer to Chart 4. There were four months that the monthly average TP concentration was above the design criteria. Chart 4. Average monthly raw sewage TP concentrations in 216 compared to 215 concentrations Raw TP Raw TP 2 Design Criteria 1 Jan Feb Mar Apr Jun Jul Aug Sep Oct Nov Dec Annual Avg. Page 5 of 14

9 Flows Detailed monthly flow information is summarized in Appendix A. The total flow treated in 216 was 28,526.1m 3, which corresponds to a 3.3% increase from 215 raw flows. The annual average daily flow was 78.2m 3 /day, or 26.1% of the plant s rated design capacity of 3m 3 /day, which is up.9% from 215. Refer to Chart 5. The design average daily flow for the plant was not exceeded in 216; maximum daily flow was 289m 3 /d. The hydraulic peak flow of 11m 3 /day for the plant was not exceeded in 216, nor was the annual average daily flow. Chart 5. Daily average raw flow for 216 compared to 215 flows Average 215 Raw Average Daily Flow (m3/d) 216 Raw Average Daily Flow (m3/d) Rated Capacity (m3/d) Limits Detailed analytical data is provided in Appendix A. Table 2 summarizes the annual averages and maximum single sample results. Page 6 of 14

10 Table 2. Monthly average effluent concentration ranges, maximum single sample effluent results, monthly average loading ranges and maximum single sample loading compared to the effluent limits prescribed in the Environmental Compliance Approval. Parameter cbod 5 Suspended Solids Total Phosphorus Monthly Average Limit Single Sample Limit Monthly Average Result Ranges Maximum Single Sample Results Monthly Loading Limit (kg/day) Monthly Average Loading ranges (kg/d) Maximum Single Sample Loading (kg/d) 1(a) 15(a) < (a) (b) 25(b) < (b) (a) 15(a) <2.2 < (a) (b) 25(b) < (b) (a) 1.(a) (a) (b) 1.5(b) (b) Total (Ammonia 3.(a) 4.5(a) < (a) Ammonium) Nitrogen 5.(b) 7.5(b) < (b) E. coli 2(a) n/a < n/a (cfu/1ml) 1(b) n/a ph (at all times) n/a Dissolved Oxygen 5(a) 4(a) n/a (Minimum Conc.) NOTE: (a) limit applies when receiving stream temps are above 5 o C (b) Limit applies when receiving stream temps are below or equal to 5 o C Discussion on Monitoring Data as Compared to the Limits The annual average effluent CBOD 5 concentration in 216 was 2.1mg/L, which is a decrease by 5% from 215 (refer to Chart 6). The annual average effluent loading for CBOD 5 in 216 was.17kg/day. The monthly average and single sample limits were met in 216 for cbod5. Refer to Table 2 for monthly average concentration, single sample concentration, and loading limits. Page 7 of 14

11 Chart 6. Monthly average concentrations of CBOD 5 in 216 compared to cbod cbod5 4 Objective 2 Limit Average Chart 7. Maximum monthly concentrations of CBOD5 in 216 compared to the maximum single sample limit Max cbod5 Single Sample Limit Average The annual average effluent Total Suspended Solids (TSS) concentration in 216 was 3.2mg/L, which is a decrease by 14.5% from 215 (refer to Chart 8). The annual average effluent loading for TSS in 216 was.25kg/day.. The monthly average and single sample limits were met in 216 for TSS. Refer to Table 2 for monthly average concentration, single sample concentration, and loading limits. Page 8 of 14

12 Chart 8. Monthly average concentrations of TSS in 216 compared to Average 215 TSS 216 TSS Objective Limit Chart 9. Maximum monthly concentrations of TSS in 216 compared to the maximum single sample limit Max TSS Single Sample Limit Average The annual average effluent Total Phosphorus (TP) concentration in 216 was.27mg/l, which is a decrease by 12.1% from 215 (refer to Chart 1). The annual average effluent loading for TP in 216 was.2kg/day. The monthly average and single sample limits were met in 216 for TP. Refer to Table 2 for monthly average concentration, single sample concentration, and loading limits. Page 9 of 14

13 Chart 1. Monthly average concentrations of TP in 216 compared to TP 216 TP Objective Limit Average Chart 11. Maximum monthly concentrations of TP in 216 compared to the maximum single sample limit Max TP Single Sample Limit The annual average effluent Total Ammonia + Ammonium Nitrogen (TAN) concentration in 216 was.35mg/l, which is a decrease by 4.2% from 215 (refer to Chart 12). The annual average effluent loading for TAN in 216 was.3kg/day. The monthly average limits were met in 216 for TAN, however, there was one single sample exceedance not met in Octember for TAN, refer to Section 3 for more detail. Refer to Table 2 for monthly average concentration, single sample concentration, and loading limits. Page 1 of 14

14 Chart 12. Monthly average concentrations of TAN in 216 compared to TAN 216 TAN Objective Limit Average Chart 13. Maximum monthly concentrations of TAN in 216 compared to the maximum single sample limit Max TAN Single Sample Limit The annual average effluent ph in 216 was 7.52, which is a decrease by 1.2% from 215. All ph readings were within the minimum and maximum limits identified in the ECA. Refer to Table 2 for ph limits. Soda ash is added at the Wardsville WWTP to control alkalinity; the addition of soda ash also increases the ph. The annual average effluent Dissolved Oxygen (DO) concentration in 216 was 1.6mg/L, which is a decrease by 3% from 215 (refer to Chart 14). DO limits were met in 216. Refer to Table 2 for monthly average concentration and single sample concentration limits. Page 11 of 14

15 Chart 14. Monthly average concentrations of DO in 216 compared to 215. Dissolved oxygen is limit is a minimum concentration required average 215 DO 216 DO Limit Min Chart 15. Minimum monthly concentrations of DO in 216 compared to the minimum single sample limit Min DO Single Sample Limit Min The annual geometric mean effluent E. coli concentration in 216 was 2.7cfu/1mL, which is a decrease by 26.6% from 215 (refer to Chart 16). The monthly geometric mean limits were met in 216 for E. coli. Refer to Table 2 for monthly geometric mean concentration limits. Page 12 of 14

16 Chart 16. Monthly geometric mean concentrations of E. coli in 216 compared to Average 215 E. coli (cfu/1ml) 216 E. coli (cfu/1ml) Objective (cfu/1ml) Limit (cfu/1ml) All monthly average compliance limits identified in the Environmental Compliance Approval were met. There was one single sample exceedance for TAN that was exceeded, refer to Section 3. Section 3: Operating Problems and Corrective Actions Routine flushing of the alum and caustic feed lines is conducted to prevent blockages of these lines. Freezing of these lines as well as the WAS/RAS lines continues to be an issue during the winter months. A single sample exceedance for TAN occurred on 25 th with a result of 11mg/L where the single sample limit is 4.5mg/L. The monthly average for met the ECA limits of 3.mg/L with an average of 2.6mg/L. Upon receiving results from the lab on 1 st, 216 for the samples taken on 25 th, 216 the Compliance Team Lead communicated with the operators of the system. In house sampling is conducted on the same day as the sample and the results were within compliance limits and the operators saw no signs of the plant being in distress. Below is a table of results for the month of, as seen in these results there is no indication of an issue prior to the non-compliance. Page 13 of 14

17 Parameter Total Ammonia Nitrogen Date Result mg/L mg/L mg/L 11.mg/L mg/L (re-assayed by lab) mg/L Section 4: Maintenance Regular scheduled monthly preventative maintenance is assigned and monitored using the Workplace Management System (WMS) program. The following is a summary of major maintenance performed other than WMS work orders: -replaced Pump 1 at Golf PS -replaced pressure relief valve on air compressor -replaced UV bulbs -repaired chemical feed pumps -repaired air compressor 2 -repaired sludge transfer pipe -replaced VFD on blowers -replaced alum pump -replaced autodailer for alarming system -removed and cleaned sand and inspected filter system Section 5: Quality Assurance quality assurance is evaluated by monitoring parameters and changes throughout the plant processes. The operators monitor the aeration tank by performing weekly tests on the mixed liquor. These tests include DO, ph, temperature, settling tests, and Mixed Liquor Suspended Solids (MLSS). As well, monitoring of the alum dosages, wasting volumes and Return Activated Sludge Suspended Solids is completed. Data collected from these test provide information to the operator to make the appropriate adjustments in the treatment process and corrective actions can be taken before the plant reaches its effluent limits. Page 14 of 14

18 Section 6: Calibration and Maintenance Annual maintenance on the generator at the Main Pumping Station was completed in by Albert s Generator Service. Flow Metrix Technical Services Inc. performed the annual calibration on the flow meter in. In house meters for ph and dissolved oxygen are calibrated by OCWA operators as per manufacturer s instructions. Section 7: Quality Objectives Detailed analytical data is provided in the excel spreadsheet in Appendix A. The following table summarizes the monthly average effluent concentrations and loadings for 216. Table 3. Monthly average effluent concentrations and loadings in 216 compared to the effluent objectives set out in the Environmental Compliance Approval. Parameter Objective Results Ranges Loading Objective (kg/day) Loading Ranges (kg/day) cbod5 5(a) < (b) < Suspended 5(a) < Solids 1(b) < Total Phosphorus Total (Ammonia + Ammonium) Nitrogen.3(a) (b) (a) < (b) < E. coli 2 28 ph NOTE: (a) limit applies when receiving stream temps are above 5 o C (b) limit applies when receiving stream temps are below or equal to 5 o C Discussion on Objectives The Wardsville WWTP did not meet the all the objectives in the Environmental Compliance Approval for 216. There were 19 objective exceedances in 216 (refer to Table 4) compared to 24 in 215. Only one of these led to a non-compliance. This was for a single sample exceedance for TAN on 25 th, 216. Upon recognizing the results have exceeded the objectives; adjustments are made to ensure that the compliance limits are not exceeded. The total phosphorus objective exceedances were mostly due to dosing issues, where there are ongoing issues with plugging of the alum lines. All actions taken are documented in the facility logbook. Page 15 of 14

19 Table 4. Exeedances of the Objectives indentified in the Environmental Compliance Approval. Parameter Date Result Comment/Cause TP 12, Higher flows, low alum dosage TP 28, Poor settling of solids in clarifier due to higher MLSS TSS 28, High MLSS TP 14, Alum line partially plugged, low alum dosage TP 12, One filter in operation TP 19, One filter in operation TP 28, One filter in operation TP 4, One filter in operation TP 23, One filter in operation ph 2, Low dosage of soda ash TP 7, Carrier water blockage, low alum dosage TSS 7, Carrier water blockage, low alum dosage TP 13, Adjusting alum dosage TP 22, Adjusting alum dosage TP 4, Alum line blockage, low alum dosage TP 13, Adjusting alum dosage TP 25, Lower DO in aeration tanks TSS 25, Lower DO in aeration tanks TAN 25, Lower DO in aeration tanks Section 8: Biosolids Management Aerobically digested biosolids produced at the Wardsville WWTP are disposed of at the Glencoe Wastewater Treatment Plant. In 216, there was no sludge removed from the Wardsville sludge holding tank. It is anticipated that in 217, 5m 3 of sludge will be removed from the holding tank. Section 9: Community Complaints There was no community complaints received for the Wardsville Wastewater Treatment Plant in 216. Page 16 of 14

20 Section 1: Bypass, Spills, and Abnormal Discharges There was no bypass or abnormal discharge events for the Wardsville WWTP for the reporting period. Section 11: Summary The Wardsville Wastewater Treatment Plant provided effective treatment in 216. There was one single sample exceedance in as described in Section 2 and 3, otherwise it met all other limits identified in the ECA. Page 17 of 14

21 APPENDIX A Analytical Data

22 Raw Flow (m3/d) Raw BOD5 Raw TSS Raw TKN Raw TP Raw Alkalinity cbod5 TSS TP TAN E. coli (cfu/1 DO ph Temp. (oc) Alkalinity Objective Concentration Objective Loading Limits >5oC Limits <5oC 216 Stream < 5 o C 216 Stream < 5 o C 216 Stream <5 o C 216 Stream >5oC 216 Stream >5oC Loading Limits Results Loading Results Loading Results Loading Results Loading Results Loading Results Loading Results Loading Results Loading Results Loading Results Loading Results Loading Results Loading Avg Max Min Sum Avg Max Min Avg Max Min Avg Max Min Avg Max Min Avg Max min Avg (4.5) < < 2.17 < 2.23 < < 2.15 < 2.13 < 2.13 < < 2.13 < 2.1 < 2.14 < 2.14 < Max 5 (1) 1.5 (3) < < 2.17 < < 2.15 < 2.13 < 2.13 < 4.28 < 2.13 < 2.13 < 2.14 < 2.14 < 4.31 Min < < 2.17 < 2.23 < 2.23 < 2.15 < 2.13 < 2.13 < 2.14 < 2.13 < 2.13 < 2.14 < 2.14 < 2.16 Avg (4.5) < 2.17 < 2.23 < 5.58 < < 3.19 < < Max 5 (1) 1.5 (3) < 2.17 < < < < 1.78 Min < 2.17 < 2.23 < 2.23 < < 2.13 < < 2.16 Avg (.3) Max.3 (.8).9 (.24) Min Avg (1.5) <.3.3 < <.1.1 < <.1.1 <.1.1 <.1.1 <.1.1 < < <.1.1 < < Max 2. (4.).6 (1.2) < < <.1.1 <.1.1 <.1.1 <.1.1 < <.1.1 <.4.3 < Min <.1.1 <.1.1 <.1.1 <.1.1 <.1.1 <.1.1 <.1.1 <.1.1 <.1.1 <.1.1 <.1.1 <.1.1 <.1.1 Geomean Max < < 2 < 2 < 2 < 2 < 2 < 2 6 < 28 Min 2. < 2 < 2 < 2 1 < 2 < 2 < < 2 < 2 < 2 < 2 < Avg Max Min Avg Max Min Avg Max Min Avg Max Min Stream >5oC 216 Stream >5oC 216 Stream >5oC 216 Stream >5oC 216 Stream >5oC 216 Stream >5oC 216 Stream <5oC Summary Annual Loading