Stonecrest Estates Sewage Treatment Plant 2017 Annual Report

Transcription

1 2017 Stonecrest Estates Sewage Treatment Plant 2017 Annual Report The Corporation of the City of Quinte West 0

2 Contents Table of Figures... 1 Executive Summary... 3 Summary and Interpretation of Monitoring Data... 5 Summary of Bypass, Spill, and abnormal discharge Events Analysis of Final Effluent Monitoring Data Carbonaceous Biochemical Oxygen Demand (CBOD) / Biochemical Oxygen Demand (BOD).. 11 Total Suspended Solids (TSS) Total Phosphorus (TP) Ammonia (NH 3 ) / Ammonium (NH 4 + ) Geometric Mean Density of E. Coli Final Effluent ph Summary and Interpretation of Final Effluent criteria associated with Micro C addition Summary of Operating Problems throughout Reporting Period Summary of Maintenance performed throughout Reporting Period Summary of Biosolids Generated in Summary of Effluent Quality Assurance and Control Measures Summary of Calibration and Maintenance carried out on Final Effluent Monitoring Equipment22 Summary of Complaints received throughout the Reporting Period Closing Remarks Table of Figures Table 1 - Summary of Monthly & Annual Average Final Effluent Concentrations... 5 Table 2 Micro C BOD Augmentation Effluent Result Summary... 6 Table 3 - Monthly & Annual Average Final Effluent Waste Loading Summary... 7 Table 4 - Summary of Raw Sewage Monthly Average Concentrations... 8 Table 5 - Plant Flow Monitoring Summary... 9 Table 6 - Summary of Bypass, Spill, and abnormal discharge Events

3 Figure 1 - Monthly Average CBOD Concentration vs. Limit & Objective Figure 2 - Monthly Average CBOD Waste Loading vs. Effluent Limit Figure 3 - Raw Sewage Concentrations vs. Effluent Concentrations Figure 4 - Final Effluent Monthly Average TSS Concentration vs. Limit & Objective Figure 5 - Final Effluent TSS Waste Loading vs. Effluent Limit Figure 6 - Raw Sewage TSS Concentration vs. Final Effluent Concentration Figure 7 - Monthly Average Effluent TP Concentration vs. Limit & Objective Figure 8 Final Effluent TP Waste Loading vs. Effluent Limit Figure 9 - Raw Sewage TP Concentration vs. Effluent TP Concentration Figure 10 - Effluent Monthly Average TAN Concentration vs. Limit & Objective Figure 11 - Final Effluent TAN Waste Loadings vs. Effluent Limit Figure 12 - Final Effluent Geometric Mean Density of E.Coli vs. Limit & Objective Figure 13 - Final Effluent ph values vs. Upper/Lower Limits Figure 14 - Annual Flow meter calibration report

4 Executive Summary The Stonecrest Estates Sewage Treatment Plant (STP), MOE Identifier number , is located at 51 Aikins Road in Bayside. The facility operates in accordance with ECA number 4460-AHBRVY issued on January 13, 2017, and previously in accordance with ECA number U3R7P, issued on March 25, The City applied for an ECA amendment to update the Works descriptions, and to introduce a BOD augmentation chemical, trade name Micro C 2000, during the timeframe the residential area was being built up. The WWTP is a Class II Treatment Plant, and is currently rated to treat 213 m 3 /d. The facility is described as a Membrane Treatment facility. The process is described as having one (1) Equalization (EQ) Tank receiving wastewater from the Stonecrest Estates subdivision, and the Bayside Secondary School. Raw sewage from the EQ tank is pumped through a fine-screen, before it is discharged into one (1) Anoxic Tank equipped with two (2) submersible pumps and one (1) mixer. Mixed Liquor from the Anoxic tank is then pumped into one (1) Aeration tank equipped with fine bubble aeration. Before Mixed Liquor is gravity-fed into the Membrane holding tank, it is dosed with Aluminum Sulphate for Phosphorus control, and Caustic Soda for ph control. A set of two (2) Permeate extraction pumps operate in a Duty/Standby configuration and place a vacuum on the membrane modules. This pulls clear liquid through the membranes, while leaving sludge and organisms behind in the membrane tank in order to increase the biological process. Final Effluent receives a UV irradiation dosage for disinfection, before final discharge into the Bay of Quinte. In accordance with ECA number 4460-AHBRVY an annual report shall be prepared within 90 days following the end of the calendar year being reported upon, detailing the following: a. A summary and interpretation of all monitoring data and a comparison to the effluent limits outlined in Condition 8, including an overview of the success and adequacy of the Works; (see pages 5 20); b. A description of any operating problems encountered and corrective actions taken; (see page 21) c. A summary of all maintenance carried out on any major structure, equipment, apparatus, mechanism or thing forming part of the Works;(see page 21) 3

5 d. A summary of any effluent quality assurance or control measures undertaken in the reporting period;(see page 22) e. A summary of the calibration and maintenance carried out on all effluent monitoring equipment; (see page 22) and, f. A description of efforts made and results achieved in meeting the Effluent Objectives of Condition 7. (see pages 5 20) g. A tabulation of the volume of sludge generated in the reporting period and an outline of anticipated volumes to be generated in the next reporting period and a summary of the locations to where the sludge was disposed; (see page 21); h. A summary of any complaints received during the reporting period and any steps taken to address the complaints;(see page 24); i. A summary of all by-pass, spill or abnormal discharge events; (see page 10); j. A copy of all Notice of Modifications submitted to the Water Supervisor as a result of Schedule B, Section 1, with a status report on the implementation of each modification; (Not applicable); k. A report summarizing all modifications completed as a result of Schedule B, Section 3; (Not applicable); and, l. Any other information the Water Supervisor requires from time to time. 4

6 Summary and Interpretation of Monitoring Data Month CBOD Monthly Average Concentration (mg/l) Objective: 5.0 mg/l Summary of Final Effluent Monthly Average & Annual Average Concentrations TSS Monthly Average TP Monthly Average TAN Monthly Average Concentration (mg/l) Concentration (mg/l) Concentration (mg/l) Objective: 5.0 mg/l Objective: 0.1 mg/l Objective: 2.0 mg/l Geometric Mean Density of E.Coli (cfu/100ml) Objective: 150 cfu/100ml Limit: 10.0 mg/l Limit: 10.0 mg/l Limit: 0.2 mg/l Limit: 3.0 mg/l Limit: 200 cfu/100ml January February March April May June July August September October November December Annual Average Table 1 - Summary of Monthly & Annual Average Final Effluent Concentrations MIN Limit: 6.0 ph MAX Limit: Monthly Average TAN Concentration exceedance voluntarily reported to MOECC on June 13, ECA Effluent Limit Conditions not in effect until May 31, Monthly Average TP Concentration exceedance reported to MOECC July 6, Monthly Average TP Concentration exceedance reported to MOECC August 10,

7 Final Effluent Results while Micro C Dosing in Effect Acute Toxicity (%) Chemical Oxygen Demand (mg/l) Dissolved Oxygen (mg/l) Sodium (mg/l) Chloride (mg/l) Month Trigger Point: Trigger Point: Trigger Point: >25 mg/l Trigger Point: <3 Trigger Point: N/A Trigger Point: >120 Lethal - DM Lethal RBT mg/l mg/l Maximum Concentration Average Concentration Minimum Concentration Maximum Concentration Maximum Concentration January February March April May June July August September October November December Annual Avg Table 2 Micro C BOD Augmentation Effluent Result Summary 4 Acute Lethality reported to MOECC on May 9, Resample collected on May 2,

8 Month Monthly CBOD Average Waste Loading (kg/d) Monthly Average and Annual Average Final Effluent Waste Loadings Annual Average Monthly Total Annual Average CBOD Waste Loading Suspended Solids TSS Waste Loading (kg/d) Average Waste (kg/d) Loading (kg/d) Monthly Total Phosphorus Waste Loading (kg/d) Annual Average TP Waste Loading (kg/d) Monthly TAN Waste Loading (kg/d) Limit: 4.25 kg/d Limit: 4.25 kg/d Limit: 0.09 kg/d Limit: 0.09 kg/d Limit: 1.28 kg/d January February March April May June July August September October November December Annual Avg Table 3 - Monthly & Annual Average Final Effluent Waste Loading Summary 7

9 Summary of Raw Sewage Monthly Average Concentrations Date Monthly Average BOD5 Concentration (mg/l) Monthly Average TSS Concentration (mg/l) Monthly Average TP Concentration (mg/l) Monthly Average TKN Concentration (mg/l) January February March April May June July August September October November December AVERAGE Table 4 - Summary of Raw Sewage Monthly Average Concentrations 8

10 Plant Flow Monitoring Data Month Average Daily Flow (m 3 /d) Max Daily Flow (m 3 /d) Total Monthly Flow (m 3 /month) Rated Capacity: 213 m 3 /d Peak Rated Capacity: 436 m 3 /d January February March April ,135 May June July August September October ,221 November ,549 December ,243 Total Plant Flow for 2017 = 10,954 m Average Daily Influent Flow = 30 m 3 /d * Operating at 14% of Rated Capacity in Table 5 - Plant Flow Monitoring Summary 9

11 Summary of Bypass, Spill, and abnormal discharge Events Table 6 - Summary of Bypass, Spill, and abnormal discharge Events Month Date Duration (hours) May July STONECREST ESTATES SEWAGE TREATMENT PLANT BYPASS AND SPILL SUMMARY Type of Bypass/Spill, Abnormal Discharge Event Volume (m 3 ) The Corporation of the City of Quinte West Results CBOD TSS TP TAN Geometric mean E. Coli May 1 NA Spill 0.05 Not applicable. Representative of diluted Raw Sewage. Material spilled onto pavement was hosed down, screenings shoveled, and disposed of. July 16 NA Spill 0.01 Not applicable. Representative of diluted Raw Sewage. Material spilled onto pavement was hosed down, screenings shoveled, and disposed of. 10

12 Analysis of Final Effluent Monitoring Data The Corporation of the City of Quinte West Carbonaceous Biochemical Oxygen Demand (CBOD) / Biochemical Oxygen Demand (BOD) The Stonecrest Estates STP had until May 31, 2017 to come into compliance with Effluent Limits established by the ECA. The facility has an Annual Average Concentration and Annual Average Waste Loading Final Effluent Limit associated with CBOD. It was established early on in the operation of the facility, that the Raw Sewage did not contain enough BOD source to support the biological growth required at the facility; therefore, a chemical named Micro C 2000 was used to supplement the BOD source until the Stonecrest development area had more homes occupied. The ECA included a chemical system shutdown date no later than November 30, It is apparent from Figure 1 that the Effluent CBOD Concentrations were maintained below the allowable Effluent Limit for the entire Reporting Period, however, bordered on the Objective. This is in part due to some of the operational issues the facility encountered during the year, and the facility still being newly in operation. Figure 2 depicts Waste Loadings well below the Effluent Limit primarily due to the low Effluent discharge flows. Figure 3 provides a good indication of the steady increase in Raw Sewage BOD Concentration throughout the year. The Annual Average CBOD Concentration in the Effluent was calculated to be 3.2 mg/l; the facility effectively removed 96.2% BOD through the treatment process. Figure 1 - Monthly Average CBOD Concentration vs. Limit & Objective 11

13 Figure 2 - Monthly Average CBOD Waste Loading vs. Effluent Limit Figure 3 - Raw Sewage Concentrations vs. Effluent Concentrations 12

14 Total Suspended Solids (TSS) It is apparent in Figures 4 and 5 that the facility consistently measured Effluent TSS below the allowable Effluent Limits, and Monthly Average Concentration Objective, throughout the Reporting Period. The facility achieved an Annual Average TSS Concentration of 2.7mg/L. A sharp increase in Raw Sewage Concentration plotted in Figure 6 occurs in March, This was due to a significant infiltration event that originated from a new property development. An excessive volume of silt/sandy water entered the facility and was pumped through the facility. The City had to empty each of the tanks, and clean the membrane cassettes manually as a result. With this, the facility has still proven effective with average 98% removal efficiency throughout the Reporting Period. Figure 4 - Final Effluent Monthly Average TSS Concentration vs. Limit & Objective 13

15 Figure 5 - Final Effluent TSS Waste Loading vs. Effluent Limit Figure 6 - Raw Sewage TSS Concentration vs. Final Effluent Concentration 14

16 Total Phosphorus (TP) The City identified early on in the operation of the facility that Raw Sewage TP concentrations are relatively high at this facility, measuring an average 4.7 mg/l annually. The facility is effectively managing TP removal throughout the bulk of the Reporting Period, however, in June and July exceeded the allowable Effluent Limit. Staff worked to understand the cause of the elevated TP concentrations, as chemical dosage modifications were not impacting the removal. It was later determined that higher ph values in the Aeration Tank were the cause of the poor removal. Staff have targeted a lower operating ph, by increasing caustic soda dosage, as a result. Figure 7 - Monthly Average Effluent TP Concentration vs. Limit & Objective 15

17 Figure 8 Final Effluent TP Waste Loading vs. Effluent Limit Figure 9 - Raw Sewage TP Concentration vs. Effluent TP Concentration 16

18 Ammonia (NH3) / Ammonium (NH4 + ) The measure of both Ammonia and Ammonium is called the Total Ammonia Nitrogen (TAN) content. Since the facility was designed to facilitate Nitrification, a Monthly Average TAN Effluent Limit and Objective have been established in the ECA. It is apparent in Figure 10 below that an issue arose in March where TAN concentration was measured well above the allowable Limit. This was due to the facility reseeding after an infiltration event, though the nitrification process quickly recovered by the next month. A second exceedance, though not quite as severe as the March event, occurred in May, The cause was a second infiltration event where the facility required reseeding. When the facility was put back online, the TAN concentration was quite high for one sample set. Similar to the earlier event, the nitrification process quickly recovered. Concentration (mg/l) Jan-17 Monthly Average Final Effluent TAN Concentrations vs. Limit and Objective Feb-17 Mar-17 Apr-17 May-17 Jun-17 Jul-17 Month Aug-17 Sep-17 Oct-17 Nov-17 Dec-17 Monthly Average Final Effluent TAN Limit (mg/l) Final Effluent TAN Objective (mg/l) Monthly Average TAN Concentration (mg/l) Figure 10 - Effluent Monthly Average TAN Concentration vs. Limit & Objective 17

19 Waste Loading (kg/d) Monthly Average Final Effluent TAN Loading vs. Limit Monthly Average Final Effluent TAN Waste Loading Limit (kg/d) Monthly Average TAN Loading (kg/d) Month Figure 11 - Final Effluent TAN Waste Loadings vs. Effluent Limit Geometric Mean Density of E. Coli Membrane treatment technology is proven effective in pathogenic organism removal, specifically E. Coli, as the pore-size of the membrane plates are smaller than an E. Coli cell. This means that E. Coli can not readily pass through a membrane. The facility has UV Disinfection in place, however sample results have shown that E. Coli concentrations, post membrane pre-uv Disinfection, are less than 2 cfu/100ml consistently, therefore the Geometric Mean Density of E. Coli has been well below the allowable Limit of 100 cfu/100ml throughout the Reporting Period. 18

20 Figure 12 - Final Effluent Geometric Mean Density of E.Coli vs. Limit & Objective Final Effluent ph 158 Final Effluent samples were collected and tested for ph throughout the Reporting Period. It is important to note that ph measurements used to determine compliance with the ECA have no QA/QC measures in place, other than routine calibration procedures of the ph probe. Figure 12 below provides evidence the ph was maintained within compliance Limits throughout the Reporting Period. Figure 13 - Final Effluent ph values vs. Upper/Lower Limits 19

21 Summary and Interpretation of Final Effluent criteria associated with Micro C addition. As mentioned previously in this Report, the facility was permitted to dose a chemical called Micro C 2000 for Raw Sewage BOD augmentation. This chemical is pumped into the Anoxic tank through odour control chemical dosing pumps. Direction provided by MOECC Approvals Branch required the City to sample and test the Final Effluent for: Acute Toxicity; Chemical Oxygen Demand; Dissolved Oxygen; Sodium; and, Chloride. A Trigger Point was assigned to most of these parameters as outlined in Table 2 Micro C BOD Augmentation Effluent Result Summary on page 6. In accordance with ECA Condition 2, the BOD augmentation system would be shut down by November 30, The City complied with this requirement, and submitted notice to MOECC on December 1, Throughout the Reporting Period, the City provided some 10 notifications of various exceedances to the Water Supervisor of the MOECC. In effort to meet the Effluent criteria, City staff reduced Micro C dosages throughout the reporting period and finished with an approximate 3 4 L of chemical used per day. 20

22 Summary of Operating Problems throughout Reporting Period Throughout the report, several operating problems encountered throughout the year have been discussed. Outlined below is a summary of those Operating Problems: Month Affected Days Description of Operating Problems March March 6-19 Facility taken offline and all process tanks emptied due to infiltration event introducing inert sand/silt material. Facility reseeded March 19, put back into service. May May 13 May 17 Facility taken offline and process tanks emptied due to infiltration event introducing inert sand/silt material. Facility seeded May 17, went online May 18. Environmental impact assessment No environmental impact. All raw sewage hauled to Trenton WWTP Collection System. No environmental impact. Raw Sewage hauled to Trenton WWTP Collection System. Summary of Maintenance performed throughout Reporting Period In addition to an active maintenance management program, Works were upgraded as follows: Headworks fine screen, screenings collector system modified. Summary of Biosolids Generated in 2017 There were no biosolids generated during the Reporting Period. At current ADF, and plant operating conditions, the facility is not expected to produce any Biosolids until

23 Summary of Effluent Quality Assurance and Control Measures The Stonecrest Estates STP Operator collects samples from Raw Sewage, Anoxic Tank, Aeration Tank, Membrane Tank, and Final Effluent on a regular basis throughout the week. The samples are tested for various parameters in-house for process control and effluent quality assurance. A spreadsheet is used to track in-house lab results and plant performance data. In addition to the in-house analysis, samples are collected weekly and sent to a certified laboratory SGS Environmental Services. These sample results are used to determine compliance with the ECA, as the City does not have approved QA/QC measures in place for their inhouse testing to qualify accuracy of results. Summary of Calibration and Maintenance carried out on Final Effluent Monitoring Equipment Work Orders are generated on a regular basis for the maintenance of the Final Effluent composite sampler and associated equipment. The Flow monitoring equipment was not captured in the Preventative Maintenance Program asset list, and was missed being calibrated with the scheduled annual work in July. It was however calibrated in January, See Figure 14 below for a copy of the annual calibration report. 22

24 Figure 14 - Annual Flow meter calibration report. 23

25 Summary of Complaints received throughout the Reporting Period There were no complaints received by City staff for the Stonecrest Estates Sewage Treatment Plant throughout the Reporting Period. Closing Remarks The Stonecrest Estates Sewage Treatment Plant is the first membrane treatment process to be installed in Quinte West. Apart from the two infiltration events that occurred during the Reporting Period, subsequently creating treatment issues wherein Effluent Limits were exceeded, the facility generally performed well. 24