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HomeMy WebLinkAboutPSD-036-07 CJMilJgton REPORT PLANNING SERVICES Meeting: GENERAL PURPOSE AND ADMINISTRATION COMMITTEE Date: Monday, March 26, 2007 Report #: PSD-036-07 File #: PLN 18.1.9 By-law #: Subject: EA NOTICE OF STUDY COMPLETION ADDITIONAL WATER POLLUTION CONTROL PLANT CAPACITY FOR THE BOWMANVILLE URBAN AREA RECOMMENDATIONS: It is respectfully recommended that the General Purpose and Administration Committee recommend to Council the following: 1. THAT Report PSD-036-07 be received for information; 2. THAT Council acknowledge that the preferred solution is the expansion of the Port Darlington Water Pollution Control plant for additional capacity to service the Bowmanville Urban Area; 3. THAT the Regional Works Department be requested to provide at an early stage of design development a site plan of high quality architectural and landscape design, such that the integration of the Plant expansion with the Port Darlington Neighbourhood and Waterfront Park can be reviewed and commented on by the Directors of Planning Services and Engineering Services; 4. THAT the Regional Works Department provide ongoing assurance and due diligence in maintaining the discharges from the Port Darlington Pollution Control Plant such that they do not impact the use and enjoyment of the Port Darlington waterfront and park; and, 5. THAT a copy of this report be forwarded to the Regional Works Department and the Ministry of Environment. Reviewed by: Q~~ Franklin Wu, Chief Administrative Officer Submitted by: Da id . Crome, M.C.I.P., R.P.P. Director of Planning Services FL/DJC/df 16 March 2007 CORPORATION OF THE MUNICIPALITY OF CLARINGTON 40 TEMPERANCE STREET, BOWMANVILLE, ONTARIO L 1C 3A6 T (905)623-3379 F (905)623-0830 REPORT NO.: PSD-036-07 PAGE 2 1.0 BACKGROUND 1.1 Durham Region completed the "Regional Sanitary Sewerage Planning Study Part IV, Municipality of Clarington (Bowmanville)" in August 1995. In February 2005 the Region of Durham informed Clarington that they would be undertaking a Class Environmental Assessment for the provision of additional water pollution control supply capacity for the Bowmanville Urban Area. 1.2 The existing water pollution control supply plant (WPCP) in Bowmanville at 93 Port Darlington Road, north of Lake Ontario has capacity available for the urban area of Bowmanville to satisfy the projected growth until 2008. 1.3 To service the estimated residential build-out population of 95,000 for the Bowmanville Urban Area additional capacity will have to be added either through the construction of a new plant, expansion of the existing Port Darlington Plant, diversion and expansion at Newcastle and/or Courtice Pollution Control Plants or limiting growth well below the estimates carried in the provincial, regional and local population projections for Bowmanville (see project summary, Attachment 1). 2.0 PREFERRED SOLUTION 2.1 Staff has been involved in the environmental assessment process and have met with the consultant and Region to ensure that the requirements of the Port Darlington Neighbourhood Secondary Plan and the capacity needs of the Bowmanville Urban Area are addressed. Staff concur with the preferred solution that recommends the expansion of the existing Port Darlington WPCP on the existing site to meet the sewage capacity needs. 2.2 While we agree with the preferred solution, the expansion of Port Darlington WPCP within the existing site includes an increase of the buffer area to the east that will effect the future subdivision development when it proceeds. . 2.3 Due to the close proximity of the WPCP to the Port Darlington Waterfront Park and Village Commercial area (see Attachment 2) the development of the expansion plan will have to be co-ordinated with any proposals for new development in the East Beach Area. As such, we are requesting that Regional Works provide a site plan of high quality architectural and landscape design to the satisfaction of the Directors of Planning Services and Engineering Services at an early stage of the design development. 2.4 The Municipality has to rely on the expertise and knowledge of the Region, their consultant and Ministry of Environment in determining the recommendations and standards regarding the proposed effluent limits. Due to location of the sewage outfall pipe and the nutrients being added to the near shore area, staff are concerned that the existing algae problem along the East Beach will be magnified. As such, we are looking to the Region to provide ongoing monitoring and exceed the non-compliance standards they are proposing such that the use and enjoyment of the Port Darlington waterfront is REPORT NO.: PSD-036-07 PAGE 3 improved by this plant expansion and not negatively impacted by discharges or the cumulative affects of the discharges. 3.0 CONCLUSIONS 3.1 The preferred solution will ensure adequate sewage capacity for the projected growth in Bowmanville, the future expansion includes provisions for servicing of the Bowmanville Urban Area including Port Darlington neighbourhood beyond 2031, with the least disruption to the natural and social environment and is economically viable. 3.2 The Staff of Clarington Planning Services and Engineering Services will continue to work with Regional Staff and consultants to ensure that the design developed for the expansion will work with the recreational facilities and park development planned for the East Beach area. . 3.3 Staff will monitor the impacts experienced along the East Beach, if any and work with Regional Staff to have them resolved. Attachments: Attachment 1 - Project Summary Attachment 2 - Map Interested parties to be notified of Council and Committee's decision: Regional Works Ministry of Environment Attachment 1 To Report PSD-036-07 J J I I The Regional Municipality of Durham is undertaking a Class Environmental Assessment (EA) study for the provision of additional wastewater treatment capacity to handle future flows from the Bowmanville Urban Area. The purpose of the study is to evaluate alternative solutions to achieving the increased capacity required, in phased steps, including expansion of the existing Port Darlington facility, pumping to the Courtice WPCP and/or development of a new plant site. The estimated residential build-out population for the Bowmanville Urban Area is approximately 95,000 persons. The estimated build-out equivalent population for the Bowmanville employment areas includes an additional 15,140 persons. Based on the projected average day sewage flows for the Bowmanville service area, the existing rated capacity of 13,638 m3/d for the Port Darlington WPCP will be exceeded by approximately the year 2008. I I I I ,~t r I Alternative solutions considered include: · Do nothing or limit growth in the Bowmanville Urban Area; · Pump sewage to the existing Newcastle WPCP; · Expand the existing Port Darlington WPCP; · Construct a new WPCP in Bowmanville; · Pump sewage to Courtice WPCP (various options including): · Option A: Maintain Port Darlington WPCP at 13,638 m3/day and pump Phase 1 expansion flows to Courtice WPCP · Option B: Decommission Port Darlington WPCP; pump all Bowmanville flows to Courtice WPCP I I I I I i... ',..1 ~- r:u! I Since the rated capacity of the Port Darlington WPCP is insufficient to handle a significant increase in population and the Region's Official Plan designates Bowmanville as an area of growth, the do nothing or limit growth in Bowmanville alternative was not considered a viable option for this study. I MacViro J::;j/.;tCG I I I I Durham Region has an existing WPCP in Newcastle, located east ofBowmanville. However, the Newcastle WPCP is a relatively small capacity facility that was designed to handle the Newcastle area only and therefore would not be able to receive the additional flows generated in Bowmanville. Therefore, pumping the sewage to the Newcastle WPCP was not considered an option for this study. :;~: (h! tiie (urn.':ji~t WPCP It was determined that the existing WPCP site has enough land space available to accommodate the Phase 1 expansion of the Plant while maintaining a 150 m buffer between sensitive residential land uses. I I I Impact on Natural Environment Expansion on the existing site will have limited impacts on the site's natural environment, as there are no vulnerable, threatened and/or endangered (VTE) species or natural heritage features present on or adjacent to the WPCP site. Also, limited vegetation removal would be required as construction would be restricted to on-site activities only. There are also no watercourses on the site to be disrupted or crossed. Impact on Social and Cultural Environments Since the majority ofthe construction activities would be contained to the existing site the expansion would have minimal social and cultural impacts on the area. It is recommended that the plant's current low vertical profile be maintained to reduce any visual impact on the local residences. This would also ensure that the plant harmonizes with the green space recreational use planned for the Port Darlington Waterfront Parklands. The proposed expansion also complies with Region of Durham and Municipality of Clarington planning policies and land use designations. There are no known archaeological or cultural issues with the site. Technical Suitability Expanding the existing plant will minimize construction and compatibility issues with the existing plant infrastructure. It will also reduce the amount of new sanitary sewer infrastructure required as the existing wastewater collection system can be used. There would be no land acquisition costs for the Phase I expansion since Durham Region currently owns the site. However, additional land may be required for the Phase 2 expansion. Operations and maintenance costs would be lower than operating two separate wastewater treatment plants. Capital and Operating Costs The capital costs for the Phase 1 expansion of the existing Port Darlington WPCP is estimated at $22 million. The Phase 2 expansion is estimated to cost $28 million. I I I I r I I I I 2 MacViro kXCG . . . . . . . . . . . . I I - - - I - 3 r Constructing a new WPCP in Bowmanville would require locating and developing a new WPCP site. As indicated in the Secondary Plan for the area and Waterfront Park Phase I Development Plan, potential new sites for facility development and construction along the Port Darlington waterfront area are very limited. A significant portion of available lands have been designated as green space, waterfront greenway and as an environmental protection area (Bowmanville Harbour Conservation Area). Considerable waterfront land space is also privately owned by St. Mary's Cement Co. and Ontario Power Generation (Darlington Nuclear Generating Station). Therefore, it would be difficult to find a suitable site for a new WPCP. It is also unlikely that a new WPCP would be constructed adjacent or close to the existing Port Darlington WPCP, therefore it has been assumed that the new plant would be designed be able to handle all flows (i.e. existing, Phase I and Phase 2). Selection of this alternative would also lead to the decommissioning of the existing Port Darlington WPCP. Impact on Natural Environment The natural environment impacts for constructing a new WPCP are unknown until a possible site is selected. There is a potential for Natural Heritage features to be present on the site. As well, vegetation may need to be removed and watercourse crossings required. Impact on Social and Cultural Environments New sites for the WPCP, potential pumping stations and sewers/forcemain would result in more locations with construction impacts affecting a greater number of residents. There is also the potential for greater visual impact on residential developments from pumping stations and a WPCP located near Lake Ontario. The Municipality of Clarington planning policy would also need to be amended (i.e., zoning) for new pumping stations and the WPCP. The costs associated with purchasing land for a new WPCP site and new sanitary sewer infrastructure would need to be incorporated into the capital costs of the WPCP. The new plant plus associated infrastructure (e.g. pumping station) may also increase the operation and maintenance costs of the new WPCP. It is also unlikely that archaeological or cultural environments would be impacted. Technical Suitability This alternative has significant technical and construction issues primarily due to greater infrastructure requirements including: · sewer infrastructure works within Bowmanville sanitary sewer system to divert flows; · new forcemain and sewers to the WPCP; · new pumping station(s); · new WPCP; MacViro ./j);XCG . related additional civil works; and . decommissioning of the existing plant 5: ~'nj tv Alternative 5, pump the wastewater generated in Bowmanville to the Courtice WPCP, has two associated options. Both options were evaluated as follows: I Option A . new pumping station(s); . new forcemain (approx. 4,OOOm); . new sewers (approx. 3,OOOm); . related additional civil works; and . may require expansion of Courtice WPCP to handle additional flows. Option B . new pumping station(s); . new forcemain (approx. 5,OOOm); . new sewers (approx. 3,OOOm); . related additional civil works; . will require expansion of Courtice WPCP to handle additional flows and decommissioning of existing Port Darlington WPCP. Impact on Natural Environment Local sewer infrastructure works will be required within the Bowmanville sanitary sewer system to divert flows from the existing WPCP to the Courtice WPCP. Since the location of the pumping station and forcemain are unknown, there potentially may be an impact on the natural environment. This would depend on the pumping station location and sewer / forcemain routes. There may also be the potential need for removal of vegetation and watercourse crossings required for the sewer / forcemain construction. Impact on Social and Cultural Environments The natural heritage, social and cultural impacts are dependent on the pumping station and forcemain routing. There may be some impacts to residents and traffic in the area from the sewer/forcemain construction, which can be minimized by limiting construction to right-of-ways. It is unlikely that the archaeological or cultural environments would be impacted. Also the Municipality of Clarington planning policies may require zoning amendments for any new pumping stations. Capital and Operating Costs The main difference between the options is related to capital costs since both options require construction of sewers, forcemains and pumping stations. Option B would require the conveyance of greater flows. The required infrastructure would generally therefore be larger in size. The Courtice WPCP is not currently operational and may not I I I I I I I I I I I 4 MacViro .,#/PXCG I Provision of Additional Water Pollution Control Plant Capacity for the Bowmanville Urban Area Municipal Class Environmental Assessment Project Summary be available to meet 2008 the expansion deadline to address over-capacity needs of the Port Darlington WPCP. There will be land acquisition costs associated with the construction of new pumping stations and potentially for sewers and forcemains. Additional capital expenditures associated with the new pumping station, forcemain and sewers as well as advancing the future expansions of Courtice WPCP, will be required. There may be other potential costs for the decommissioning of the Port Darlington WPCP if required. Current estimated capital costs associated with each option are as follows: . Option A: Phase I: $42 million and Phase 2: $25 million . Option B: Phase I: $62 million and Phase 2: $29 million The preferred solution for the Phase 1 expansion is a doubling ofthe existing capacity of the Port Darlington WPCP from 13,638 m3/d to 27,276 m3/d. This will allow for sufficient plant capacity to treat projected sewage flows up to approximately the year 2023. Sufficient land is also available on-site for a further (Phase 2) expansion of the Plant after 2023. The proposed expansion will ensure that a 150 m buffer between potential emissions sources and all sensitive land uses in the vicinity of the plant is maintained. K t to'~'i ~VPCf~ The existing Port Darlington WPCP consists of a conventional activated sludge process with anaerobic digestion of the mixed sludge (primary and waste activated sludge). The plant was constructed in 1982 with a rated capacity of 4,546 m3/d including treatment trains No.1 and 2. A subsequent expansion in 1992 increased the plant capacity to its existing 13,638 m3/d by adding two additional treatment trains No.3 and 4. Sewage inflows to the plant are conveyed via a 1200 mm diameter sanitary trunk sewer. Plant effluent is discharged through a 1350 mm and 1200 mm diameter outfall pipe into Lake Ontario. The existing Port Darlington WPCP effluent objectives and non-compliance limits are presented in Table 1. 5 MacViro h:fXCG Provision of Additional Water Pollution Control Plant Capacity for the Bowmanville Urban Area Municipal Class Environmental Assessment Project Sllmmary T bl 1 C t Effl Ob. dN C l' L' . a e urren uent ~echves an on- ompJ lance lmlts Parameter Effluent Objectives Non-Compliance Limits Concentration Loading Concentration Loading(4) BOOo(1) 15 mg/L 511.43 kg/d 25 mg/L 852.40 kg/d T88(1) 15 mg/L 511.43 kg/d 25 mg/L 852.40 kg/d TP(2) 1 mg/L 34.10 kg/d 1.0 mg/L 34.10 kg/d Ammonia 14 mg/L 477.33 kg/d (as N)(3) - - Total Chlorine 0.5 mg/L 17.00 kg/d - - Residual (1) Yearly average of monthly samples. (2) Monthly average of weekly samples. (3) Weekly samples required. (4) Mass loading based on average concentration (yearly for BO~s. T88, and monthly for TP) multiplied by the daily average flow during the averaging period. Because of the 5-year applicability of this Class EA Study, alternative solutions and the development of recommendations for the conceptual design of the Phase 2 expansion of water pollution control plant capacity for the Bowmanville Urban Area will need to be re- evaluated prior to the implementation of the Phase II expansion. It is recognized however, that a meaningful preferred servicing solution for the Phase 1 capacity expansion can not be developed without considering the potential for all future treatment capacity expansions to occur at the Port Darlington WPCP site. Proposed effluent criteria presented in this Technical Memorandum are therefore based on the expansion of the Port Darlington WPCP to handle all Phase 1 and Phase 2 wastewater flows. This conservative approach is particularly applicable to our mixing zone analysis, for which Phase 2 flows and proposed effluent limits were used to establish effluent plume limits that would achieve compliance with PWQO. BODs and TSS Lake Ontario, in the Bowmanville area, is also Policy I for dissolved oxygen (DO). For BODs and TSS limits, we therefore propose that the existing non-compliance limit of 25 mglL be maintained for both. Phosphorus Lake Ontario is generally designated Policy 1 for total phosphorus (TP). This has been confirmed by analyzing Lake Ontario TP data in the vicinity of Bowmanville collected by Environment Canada between 1993 and 2004. The average TP was found to be 0.007 mg/L with the 75th percentile TP at 0.008 mg/L. These values are significantly less than the Provincial Water Quality Objective (PWQO) of 0.02 mg/L for total phosphorus in lakes. Therefore, it is not expected that increased TP effluent loadings resulting from the 6 Ma<;:Viro I I I I I I I I I I I I I I I - I 7 - expanded plant flows will be sufficient to cause the above PWQO limit to be exceeded. It is proposed that the existing TP non-compliance limit of 1.0 mg/L be maintained for the expanded water pollution control plant capacity. The existing TP loading limit is 34.1 kg/d. For Phase 1 Port Darlington WPCP flowrates, it is estimated that the TP loading limit will be 68.2 kg/d. For Phase 2 flowrates, it is estimated that the TP loading limit will be 102.3 kg/d. Ammonia With respect to ammonia limits, it is anticipated that the Ministry of the Environment's current policy of requiring a non-toxic effluent for all new and/or expanded wastewater treatment plants would apply. A conservative guideline of 0.1 mg/L un-ionized ammonia to ensure a non-toxic effluent (end-of-pipe) is therefore typically used. In order to calculate the effluent toxicity, data on the pH and temperature of the effluent are required. Port Darlington WPCP effluent pH measurements for the years 2003 to 2004 were utilized. However, there is no temperature data available for the Port Darlington WPCP effluent. Wastewater effluent temperature data is available for the Corbett Creek, Duffin Creek and Harmony Creek WPCP's. As temperature and pH increases, the percentage of ammonia which remains un-ionized also increases. Therefore, utilizing Corbett Creek WPCP temperature data for our analysis will result in the worst-case un-ionized ammonia concentration (and therefore the most conservative effluent criteria). In accordance with accepted practice, monthly 75th percentile figures rather than monthly average values, were used for the pH data to ensure that the monthly estimates of un-ionized ammonia were conservatively calculated. Based on the temperature and pH data available, ifthe effluent ammonia (N) limit was reduced to 14 mg/L in the summer and 28 mg/l in the winter, effluent un-ionized ammonia levels were determined to be well below the toxic threshold of 0.1 0 mg/L. Based on this analysis, utilizing the revised proposed ammonia as N effluent limits of 14 mg/L (summer) and 24 mg/L (winter) for the Port Darlington WPCP Phase 1 expansion fully complies with the Ministry's established end-of-pipe un- ionized ammonia limits. Therefore a non-compliance limit of 24 mg/L in the winter and 14 mg/L in the summer is recommended. E. Coli Sewage discharges to surface waters can constitute a significant input source of pathogens to the receiving waters. Therefore, to protect the recreational use of Lake Ontario in the vicinity of the Port Darlington WPCP, it is recommended that the expanded plant include a non-compliance limit for E. coli of200 counts/100 mL. Proposed Effluent Limits Based on the above rationale, recommended effluent non-compliance limits for expansion of the water pollution control plant capacity for the Bowmanville Urban Area are as shown in Table 3 below. MacViro .,:lFXCG I I I I I I I I I I I I I I I I . . 8 . Table 3A - Proposed Effluent Concentration Limits Non-Compliance Limits Parameter Average Concentration Existing Rated Phase 1 Expansion to Phase 2 Expansion to Capacity 13,638 m3/d 27,276 m3/d 40,477 m3/d BODs (mg/L) Monthly Average 25 25 25 TSS (mg/L) Monthly Average 25 25 25 Total Phosphorus Monthly Average 1 1 1 (mg/L) Total Ammonia as N Monthly Average 14 14 (mg/L) - Summer -- Total Ammonia as N Monthly Average 24 24 (mg/L) - Winter -- E. coli (org./100 mL) Monthly Average -- 200 200 Total Residual Monthly Average 0.02 0.02 Chlorine (mg/L) -- Table 3B - Proposed Effluent Loading Limits Non-Complia"ce Limits Parameter Average Loading (kg/d) Phase 1 Expansion to 27,276 m3/d Phase 2 Expansion to 40,477 m3/d BODs (mg/L) Monthly Average 681.9 1011.9 TSS (mg/L) Monthly Average 681.9 1011.9 Total Phosphorus Monthly Average 27.3 40,5 (mgiL) Total Ammonia as N Monthly Average 381,9 566.7 (mg/L) - Summer Total Ammonia as N Monthly Average 654.6 971.4 (mg/L) - Winter ; To achieve the above design criteria, the following new unit processes are recommended for the expansion of the existing Port Darlington WPCP: . screenmg raw sewage pumping station grit removal primary treatment conventional activated sludge (bioreactors designed for enhanced nitrogen removal) . . . . MacViro .ij]:-XCG I I . secondary clarification . phosphorous removal . disinfection · anaerobic digestion Capital cost estimates for the Phase I expansion are provided in Table 4. The cost estimates include allowances for site works, inlet works, preliminary treatment (i.e. screening and grit removal), primary treatment, biological treatment, effluent disinfection, and sludge stabilization. The costs also include allowances for engineering, contingencies and taxes. I I I I Table 4 Capital Cost Estimate for Phase I Expansion I Process Component Estimated Capital Cost Phase 1 Expansion Site Works $900,000 Raw Sewaqe Pumpinq Station $300,000 Septaqe Receivinq Station $500,000 Screeninq $500,000 Grit Channels $300,000 Primary Clarification $1,750,000 Aeration Tank and Blower Buildinq $4,500,000 Secondary Clarification $3,000,000 Chemical Dosinq System (P-removal) $750,000 UV Disinfection Facility $1,350,000 Anaerobic Diqestion $3,000,000 Stand-by Power $500,000 Sub-total $17,350,000 Approvals $100,000 Engineering (@ 10%) $1,735,000 Contingencies (@ 15%) $2,602,500 TOTAL $21,787,500 I I I I I I I I These cost estimates have been developed at a planning level of accuracy and will be reviewed and updated during the preliminary and detailed design stages of the Phase 1 expanSIOn. I I I 9 I MacViro .IiiXCG Attachment 2 To Report PSD-036-07 >. - .- c: '0 :> "'C c: cu CI) ~ tJ) - c: cu - D. - o ~ - c: o (J c: o ;:; ~ - - o D. ~ CI) - cu 3: c: o - C) c: .- i: cu C t:: o D.