Town of South Bruce Peninsula

Transcription

1 Town of South Bruce Peninsula Wiarton Wastewater Treatment Plant Municipal Class Environmental Assessment (Schedule C) Environmental Study Report Type of Document FINAL REPORT Project Number exp Services Inc Clark Blvd Brampton, ON L6T 4V1 Canada Date Submitted

2

3 Wiarton Wastewater Treatment Plant Municipal Class Environmental Assessment (Schedule C) Environmental Study Report Type of Document: FINAL REPORT Project Number: exp Services Inc Clark Blvd Brampton, ON L6T 4V1 Canada T: F: Date Submitted:

4 Legal Notification This report was prepared by exp Services Inc. for the account of Town of South Bruce Peninsula. Any use which a third party makes of this report, or any reliance on or decisions to be made based on it, are the responsibility of such third parties. Exp Services Inc. accepts no responsibility for damages, if any, suffered by any third party as a result of decisions made or actions based on this project. ii

5 Table of Contents 1 Introduction Overview Municipal Class Environmental Assessment Process Objectives of the ESR Problem Statement Introduction Required Improvements Changes to Federal and Provincial Wastewater Effluent Standards Summary Existing Conditions Existing Wastewater Treatment Plant Collection Network Wastewater Treatment Plant Components Wastewater Treatment Plant Performance Natural Environment Site Description Natural Areas Regulated Conservation Areas Socio-Economic Environment Official Plan Niagara Escarpment Plan Grey Sauble Conservation Authority Surrounding Land Uses Archaeological Assessment Alternative Solutions Pre-Screening of Alternative Solution Categories Identification of Alternative Solutions Alternative 1: Add Integrated Fixed-film System (IFS) with Nitrification Screening of Alternative Solutions Evaluation of Screened Alternatives iii

6 4.4.1 Evaluation Criteria Preferred Alternative Solution Phase 3 - Alternative Designs Review of Alternative Designs Alternative Design # Alternative Design # Alternative Design # Evaluation of Alternative Designs Evaluation Criteria Evaluation Summary Proposed Solution and Approval Requirements Proposed Solution Approvals Stakeholder Consultation Public Consultation Agency Consultation Ministry of Environment and Climate Change Grey Sauble Conservation Authority Niagara Escarpment Commission Ministry of Tourism, Culture and Sport First Nations, Aboriginal Group and Metis Consultation iv

7 List of Appendices Appendix A: Natural Sciences Report Appendix B: Archaeological Assessment Report Appendix C: Township of Georgian Bluffs Zoning By-law Amendment Application and Notice of Passing Appendix D: Screening for Impacts to Built Heritage and Cultural Heritage Landscapes Appendix E: Notice of Commencement and Consultation Contact List Appendix F: Public Information Centres 1 and 2 Appendix G: Council Delegations and Minutes Appendix H: Agency Correspondence Appendix I: First Nations, Aboriginal Group and Metis Consultation List of Tables Table 1: Wiarton WWTP Performance (2011 to 2013) Table 2: Pre-screening of Alternative Solution Categories Table 3: Alternative Solutions Screening Results Table 4: Alternative Solution Evaluation Criteria Table 5: Evaluation against Technical Criteria Table 6: Evaluation against Natural Environment Criteria Table 7: Evaluation against Social/Cultural Criteria Table 8: Evaluation against Financial Criteria Table 9: Alternative Design Evaluation Criteria Table 10: Alternative Design Evaluation Summary List of Figures Figure 1: Municipal Class EA Planning and Design Process... 3 Figure 2: Study Area... 6 Figure 3: Existing Wiarton WWTP... 7 Figure 4: Conservation Authority Regulated Areas on Project Site Figure 5: Alternative Solution 1 IFS with Nitrification Figure 6: Alternative Solution 2 Lagoon Deepening with Nitrification Figure 7: Alternative Solution 3 Activated Sludge Figure 8: Alternative Design # Figure 9: Alternative Design # Figure 10: Alternative Design # v

8 1 Introduction 1.1 Overview Wiarton is a community within the Town of South Bruce Peninsula. According to the Town s Official Plan, the community is a major urban settlement area for the Town and functions as a regional service centre. The community was incorporated as a Town in 1894 and amalgamated into the current Town of South Bruce Peninsula in 1999, along with the Village of Hepworth, and the Townships of Amabel and Albermarle. In 2011, the community had a population of 2, While the community s population has experienced a slight decrease in the past decade (a decrease of 2.5% between 2001 and 2011), there has also been a slight increase in the number of private dwellings in the same time period (an increase of 3.3%). However, an analysis completed in 2015 during the Wiarton Master Servicing Study estimates that the community s population will grow to 5,729 by The community of Wiarton s wastewater is treated by the Wiarton Wastewater Treatment Plant (WWTP). The WWTP is located within the Township of Georgian Bluffs, Grey County, just south of the boundary of the community of Wiarton. The WWTP receives wastewater collected within the community; it also accepts septage from within and outside of Wiarton. The WWTP has an average annual rated capacity of 2,500 m3 per year, which is not sufficient to accommodate the residential and employment growth anticipated in Wiarton. The septage handling at the plant is also not streamlined. Increasing the capacity of the WWTP to meet the community s anticipated wastewater treatment demands requires the completion of a Municipal Class Environmental Assessment (Municipal Engineers Association, 2007, amended 2011). The purpose of this Environmental Study Report (ESR) is to document the process undertaken for the Town to identify a preferred solution for addressing the wastewater treatment servicing needs for the community of Wiarton, including the preferred design of the upgraded facility. 1.2 Municipal Class Environmental Assessment Process All Municipalities in Ontario are subject to the provisions of the Ontario Environmental Assessment Act (EAA) and its requirements to prepare an EA for applicable public works projects. These requirements can be met by following the Municipal Class Environmental Assessment (Class EA) Process as described by the Ontario Municipal Engineers Association (MEA) Municipal Class Environmental Assessment document (2007, amended 2011). The Municipal Class EA applies to a group or class of municipal water, wastewater and road projects that occur relatively frequently and have relatively minor and predictable impacts. Class EA projects fall into four schedules (i.e. categories) of undertakings depending on the extent of their potential impact. These include: Schedule A: Includes normal or emergency operational and maintenance activities; projects have minimal environmental effects and are pre-approved; Schedule A+: Projects are pre-approved, but public is to be advised of project before implementation; 1 Statistics Canada, 2011 Census of Population. 1

9 Schedule B: Includes improvements and minor expansions to existing facilities; projects may have potential for some adverse environmental impacts, therefore a screening process including consultation with potentially affected stakeholders required; Schedule C: Includes construction of new facilities or major expansions to existing facilities; project may have potential for significant environmental effects and must proceed through full Class EA planning process. Expansion of an existing sewage treatment plant beyond its existing rated capacity is classified as a Schedule C project. Therefore, this Class EA is designated as a Schedule C Class EA. There are five phases to a Schedule C Class EA process. These include: Phase 1: Identify the problem (deficiency) or opportunity: Identify the problem or the opportunity that the Class EA is intended to address. Phase 2: Identify and Evaluate Alternative Solutions: Identify alternative solutions to the problem or opportunity by taking into consideration the existing environment and establish the preferred solution accounting for public and agency review and input. Document the planning process in a Municipal Class EA project file and make such documentation available for scrutiny by review agencies and the public. Phase 3: Evaluation of Alternative Design Concepts: For Schedule C projects, examine alternative methods of implementing the preferred solution based upon the existing environment, public and government agency input, anticipated environmental effects, and methods of minimizing negative effects and maximizing positive effects. Phase 4: Environmental Study Report (ESR): For Schedule C projects, document, in an Environmental Study Report (ESR), a summary of the rationale and the planning, design and consultation process followed in the project and make such documentation available for scrutiny by review agencies and the public. Phase 5: Implementation: Complete contract drawings and documents, proceed to construction and operation and monitor construction for adherence to environmental provisions and commitments. Where special conditions dictate, also monitor the operation of the completed facilities. Figure 1 illustrates the Municipal Class EA process. 2

10 Figure 1: Municipal Class EA Planning and Design Process 3

11 1.3 Objectives of the ESR This ESR has been prepared to meet the requirements of the MEA Municipal Class EA planning process. The objectives of this ESR document include: Provide background information on the WWTP and the need for additional wastewater treatment capacity; Present the alternative solutions to provide the needed additional capacity and the rationale for selecting the preferred solution; Present the alternative design concepts for the preferred solution and the rationale for selecting the preferred design concepts; Provide a description of the potential environmental effects associated with construction and operation of the preferred design concept and proposed mitigating measures to minimize environmental effects; and Document the consultation process with an explanation of how concerns raised by the public and review agencies have been addressed in developing this project. The different sections of this ESR include: Section 1 Provides an introduction to the project, the Class EA process and the structure of this ESR. Section 2 presents the Problem Statement for this project. Section 3 reviews the existing conditions for this project. Section 4 identifies and evaluates the alternative solutions for this project. Section 5 reviews and identifies the alternative designs for the preferred solution. Section 6 presents the proposed project and approval requirements. Section 7 discusses the consultation with public, agencies and stakeholders undertaken during the Class EA process. 4

12 2 Problem Statement 2.1 Introduction The Community of Wiarton is a small south-west Ontario community located on the shores of Colpoys Bay, an Inlet on Georgian Bay. It is part of the Town of South Bruce Peninsula (TSBP), which was created in 1999 through the amalgamation of the Town of Wiarton, Village of Hepworth, and the Townships of Amabel and Albermarie. According to the 2011 Census, the community had a population of 2,291, with 1,100 households (private dwellings) 2. The Town s sewage and wastewater is treated by the Town s wastewater treatment plant (WWTP), located off of Elm Street, south of Taylor Street. The WWTP is operated by the Ontario Clean Water Agency and receives wastewater and sewage from Wiarton s wastewater collection system as well as septage and holding tank waste from homes and businesses in the area. The facility has an approved average daily capacity of 2,500 m 3 per day. In 2013, the average daily flow was 1,946 m 3 /day, or about 78% of capacity. The Town s WWTP is facing some key challenges in its operation. These relate to an increasing demand on its capacity and changes to federal and provincial standards for wastewater effluent. 2.2 Required Improvements The community of Wiarton is designated by the TSBP Official Plan (OP) as a Primary Urban Community and is classified as a Primary Settlement Area. As a primary settlement area, the OP directs major residential growth to be directed to the Community of Wiarton. Based on analysis completed for Wiarton s Master Servicing Plan, it is expected that Wiarton s population will increase to approximately 5,729 by the year Further, the on-going Master Servicing Plan study estimates that the WWTP will be required to manage approximately 4,395 m 3 /day (say 4400 m 3 /day) of wastewater by This exceeds the current capacity of the Wiarton WWTP. In addition, it is also noted that the WWTP does not have a proper septage receiving station. 2.3 Changes to Federal and Provincial Wastewater Effluent Standards Effluent from the WWTP is required to meet various environmental limits (e.g., biological oxygen demand, suspended solids, etc) as per the terms and conditions of its Certificate of Approval (C of A). T WWTP has been meeting its effluent limits. Currently, the WWTP s C of A does not include effluent limits for ammonia. However, in 2012 the federal government introduced regulations that set new wastewater effluent limits for ammonia (1.25mg/L), which come into force January The MOECC has also advised that its own standards for ammonia limits (still under development) would likely be more stringent than the federal limits. The average ammonia concentrations in the community s WWTP effluent has ranged between 2.3 mg/l and 4.4 mg/l from 2011 to 2013, which would not be in compliance with the new federal regulations. 2 Statistics Canada, 2011 Census of Population. 3 GM BluePlan Engineering. Memorandum - Wiarton Master Servicing Plan: Wastewater Baseline and Future Criteria Summary. January 20,

13 2.4 Summary Wiarton s current WWTP does not have the capacity required to meet its projected wastewater treatment demands based on the growth of the community and on increased septage delivered to the facility. Further, the WWTP in its existing form would not be able to meet the new federal and provincial ammonia limits coming into effect in The Town of Wiarton is undertaking this Municipal Class EA to identify solutions to the projected capacity shortfall and to ensure the WWTP is able to meet upcoming effluent limits and create better septage handling facility. The study area for the proposed study is depicted in Figure 2. Figure 2: Study Area 6

14 3 Existing Conditions 3.1 Existing Wastewater Treatment Plant Collection Network Wiarton s existing wastewater treatment system is comprised of a wastewater collection network, which collects and transports the community s wastewater to a treatment plant (WWTP), which in turn discharges treated effluent via an outfall to Colpoy s Bay (note that this Class EA scope only includes the wastewater treatment plant). The wastewater collection system uses a series of two sewage pumping stations. Sewage from the community sewers empty into Sewage Pumping Station #1 (SPS #1), which is located on Taylor Street next to the Wiarton Community Centre. SPS#1 has two 60 HP pumps (one duty, one standby), each with a rated capacity of 103 L/s and a TDH of 29 m. The combined rated capacity for the pumps is 130 L/s at a TDH of 39 m. SPS#1 pumps the sewage to Sewage Pumping Station #2 (SPS#2), which is located next to the Wiarton Cemetery on Elm Street and has three pumps (one duty, two standby). At SPS#2, two pumps running in parallel have a combined rated capacity of L/s at a TDH of m Wastewater Treatment Plant Components The existing WWTP is a lagoon-based treatment system. There are three waste stabilization lagoons (also referred to as cells) that cover a total area of approximately 6 ha. The lagoons have a nominal depth of 1.52 m. Cell 1 includes a fine bubble aeration system, while Cells 2 and 3 provide less aeration compared to Cell 1. Figure 2 illustrates the wastewater treatment plant and its components. Figure 3: Existing Wiarton WWTP 7

15 All lagoons have submerged air diffusion systems that consist of header feeder pipes and distribution diffusion tubes, installed across the cells as follows: Cell No. 1: Thirty-seven lines at spacing varying from 3.05 m to 6.1 m centre to centre; Cell No. 2: Ten lines at spacing of 17 m centre to centre; Cell No. 3: Five lines at spacing of 38 m centre to centre; Two rotary positive displacement blowers, each rated at 165 L/sec against a head of 42 kpa (one as standby) and belt driven by 15 kw motors; A fine-bubble aeration system in Cell 1, including new air header and lateral pipes and membrane diffusion tubes. A 300 mm forcemain from SPS #2 brings in sewage influent to a flow splitter box located between Cells 1 and 2. The splitter allows influent flow to be divided between the two cells on an as-needed basis. A lagoon facility control building is used to house the blowers for the aeration system. The 10.6 m x 6.9 m building accommodates the following: Two motor driven blowers complete with connecting pipework and all necessary appurtenances; Motor control centre, work bench and washroom facility; and Yard piping, electrical power supply and equipment, heating and ventilation equipment and all other necessary appurtenances and controls. The WWTP includes a phosphorus removal system. Polymer Kemira PAS-XL-308F and Alum are added for coagulation and flocculation purposes to settle phosphorus out. The phosphorus removal system is comprised of the following: A 22,700 L chemical storage tank for storage of phosphorus removal chemical; and Two positive displacement-type chemical metering pumps (one on standby), each capable of pumping 41 L/hr at 1034 kpa, for dosing phosphorus-removal chemicals to the sewage at a dosing point located in the outlet forcemain. After the phosphorus removal, the wastewater effluent is directed through an effluent filtration plant, which is comprised of a Dynasand Effluent Filtration system with a peak design flow capacity of 5,734 m 3 /day. The filtration system is located in a building on the north side of the facility and includes: Three effluent filter cells, each cell having two filter modules, providing a total filtration area of 27.9 m 2 and filtration depth of 2.0 m, equipped with air compressors for continuous filter backwash, influent flow measurement weir with ultrasonic level detector, and a bypass weir to allow filter bypass during events of high peak flows exceeding 5,734 m3/day; One 3.0 m diameter and 6.5 m deep precast concrete wet well for receiving filter backwash and septage, equipped with two submersible pumps each with a capacity of m TDH and a 2.7 m x 2.1 m precast valve chamber, discharging into Cell No. 1 through a 200 mm diameter forcemain; 8

16 One 12,000 L capacity coagulant storage tank (2.13 m diameter x 3.5 m high), equipped with two coagulant metering pumps (one duty and one standby) dosing coagulant at a flow paced rate upstream of the filtration units; A third rotary positive displacement blower rated at 165 L/sec against a head of 42 kpa and belt driven by 15 kw motors (standby blower). Prior to discharge, the effluent goes through an ultraviolet disinfection system (Wedeco Model TAK55M 6-2), which is designed for a peak flow rate of 8,000 m3/day. The disinfection system consists of: One UV disinfection unit with approximate dimensions of 2.0 m long x m wide x m minimum water depth, containing one UV bank with two UV modules each with 12 high intensity low pressure UV lamps ( a total of 24 lamps), designed to provide a 30.0 mj/cm2 UV dosage at 55 % Transmittance at 254 nm during peak design flow of 8,000 m3/day; Provision of a hypochlorite solution storage tank complete with 100% spill containment, and an L/hr capacity metering pump for seasonal chlorination of lagoon effluent (before filtration and UV disinfection) for control of algae growth between May and September of each year Wastewater Treatment Plant Performance The WWTP operates under a Certificate of Approval (C of A) from the Ontario Ministry of Environment and Climate Change (MOECC). The C of A sets conditions under which the WWTP must operate, in particular limits for average daily flow 4 and concentrations of effluent contaminants. Monitoring reports for the WWTP indicate that the WWTP is operating within these limits. However, the maximum capacity utilization at the plant has been nearly 80% over last three years. Table 1 presents the sewage and effluent limits for the WWTP and the Plant s performance from 2011 to While the WWTP is performing relatively well with respect to ammonia removal, the levels measured from 2011 to 2013 exceed the new ammonia limits introduced by the Federal Government under the Wastewater Systems Effluent Regulations, which are in force effective January The new federal standards set average concentration limits in effluent for ammonia at 1.25 mg/l. Consultation with MOECC also indicate that the MOECC may be considering effluent concentration limits for ammonia that are lower than the federal standard. As Table 1 shows, the WWTP would not have met those limits in 2011 to Average daily flow is the total amount of sewage treated per annum divided by the number of days of operation. 9

17 Table 1: Wiarton WWTP Performance (2011 to 2013) Year Average Day Flow Maximum Day Flow ,992 cubic m/d 8,745 cubic m/d ,430 cubic m/d 5,851 cubic m/d ,946 cubic m/d 11,158 cubic m/d Applicable C of A N/A Standard 2,5000 cubic m/d Effluent BOD Effluent S.S. Effluent TP Effluent Ammonia Septage Volume 2.6 mg/l 4.6 mg/l 0.18 mg/l 4.4 mg/l Approx. 5 cubic m/d 5 mg/l 13 mg/l 0.18 mg/l 2.3 mg/l Approx. 4.1 cubic m/d 3.5 mg/l 7.3 mg/l 0.17 mg/l 3.0 mg/l Approx. 5 cubic m/d C of A C of A C of A N/A Effluent Effluent Effluent Objective: Objective: Objective: 15 mg/l 15 mg/l 0.3 mg/l C of A Effluent Limit: 20 mg/l C of A Effluent Limit: 24 mg/l C of A Effluent Limit: 0.5 mg/l C of A Effluent Objective: 3.0 mg/l (May Nov) 8.0 mg/l (Dec Apr) No C of A Effluent Limit Federal Standard: 1.25 mg/l 3.2 Natural Environment The natural environment of the project study area and surroundings is provided below. Additional information is provided in the Natural Sciences Report, provided in Appendix A Site Description The lands in the vicinity of the WWTP are primarily under agricultural land use, although rural residential properties and a cemetery also border the site. The borrow pit area adjacent to the southernmost existing lagoon functions as a small man-made wetland as a result of disturbance on the site and drains to an unnamed watercourse, which flows into the Taylor Street detention pond and ultimately to Colpoy s Bay Natural Areas The most prominent natural feature of the general area is the Niagara Escarpment. The Escarpment is a designated UNESCO World Biosphere Reserve and forms the spine of the Bruce Peninsula. Natural heritage features associated with the Escarpment have been afforded protection through the formation of several parks and reserves in the area and through various types of legislation; most notably, the Niagara Escarpment Planning and Development Act. The WWTP property straddles two NEPDA designated areas. A portion of the property is designated as Escarpment Protection Area and Escarpment Rural Area. Out of the 3 existing wastewater lagoons, 2 are under the NEPDA area, while the 10

18 southernmost lagoon is outside of this area. A permit will be required from the Niagara Escarpment Commission (NEC) prior to any work being conducted on the site. The Natural Sciences investigation determined that no Areas of Natural and Scientific Interest (ANSIs) were located within or in proximity to the project site. The Lands Information Ontario (LIO) database, maintained by the Ministry of Natural Resources, did not indicate the presence of any wetlands on the project site. The closest wetland features documented through the LIO are unevaluated wetlands located to the southeast. Two provincially significant wetlands (PSW), the Rankin River PSW and the Oxenden Creek PSW, are located at least 2.5 km away from the project site, while the Wiarton Wetland Complex is located approximately 2 km away. Given the distance of these features from the WWTP site and that surface drainage on the property is documented as generally in a northwest direction toward Colpoy s Bay, the potential for impacts to these features as a result of activities on the WWTP site is considered low. Natural hazard features include valley lands. While no natural hazard features are identified on the project property in the Grey County Official Plan, the Grey Sauble Conservation Authority (GSCA) indicates the presence of natural hazards in the form of a man-made wetland feature (i.e., the borrow pit) and drains identified on site. Review of contour mapping conducted for the natural sciences report does not suggest the presence of any large valley systems or any substantial changes in topography beyond what has been identified by GSCA. No woodlands were identified on the subject property using data available in LIO or mapping provided in the upper and lower tier Official Plans. Woodlands are documented on lands adjacent to the site, on the north side of Elm Street and along the southern edge of the parcel boundary. The County of Bruce Official Plan identifies the woodlands located to the northwest and northeast of the project area as significant, while the County of Grey Official Plan identifies the woodland on the southern property boundary as significant. These woodlands are located approximately 250 m north of the project study area and 200 m south and as such are outside the project study area. The Natural Sciences investigation reported that the GSCA finds it highly probable that the borrow pit is functioning as amphibian breeding habitat. The agency is also reportedly aware of a record in the Natural Heritage Information Centre (NHIC) Biodiversity database, which is maintained by the Ministry of Natural Resources, for a species of Special Concern associated with the lagoons on site. The site does fall within the range of some Species at Risk (SAR); therefore, there is the potential for SAR where habitat exists on the WWTP property. In-season investigation will be required to confirm conditions as they relate to vegetation communities and the potential for SAR habitat. The Natural Sciences investigation reports that GSCA records include an observation of fish occurring at a culvert adjacent to the WWTP property. The wetland feature and drain are connected to this feature and therefore contribute indirectly to fish habitat Regulated Conservation Areas Portions of the project site are regulated under Ontario Regulation 151/06 to include a wetland feature and several drain features connected to a watercourse. A Permit will be required from the GSCA prior to any work being conducted within these regulation limits. See Figure 3 for regulation limits within project study area. 11

19 Figure 4: Conservation Authority Regulated Areas on Project Site Project Area 12

20 3.3 Socio-Economic Environment Official Plan Although the WWTP is owned and operated by the Town of South Bruce Peninsula, the facility property is in fact located in the Township of Georgian Bluffs, in the County of Grey. As such, the WWTP falls under the Official Plans for the Town of South Bruce Peninsula, the Township of Georgian Bluffs, and the County of Grey. While the County of Bruce Official Plan does address wastewater and sewage servicing and the issue of available servicing capacity, it does not address specifically the Wiarton WWTP or the property. With respect to the Township of Georgian Bluffs Official Plan, the study area is not within any land use policy areas for the Township, although the northern portion of the study area is within the Development Control Area of the Niagara Escarpment Plan. A portion of the study area falls within areas designated as agricultural in the County of Grey Official Plan; however, provisions in the County of Grey Official Plan permit utilities and other infrastructure in agricultural areas Niagara Escarpment Plan As noted above, a portion of the study area is located within an Escarpment Protection Area as designated by the Niagara Escarpment Plan, which is administered by the Niagara Escarpment Commission (NEC). The purpose of the Niagara Escarpment Plan is the protection of the remaining natural features and the open, rural landscape character of the Escarpment and lands in its vicinity. Utility uses, including sanitary sewage systems, are permitted within Protected Areas. (NEP, s.1.4) Grey Sauble Conservation Authority The Study Area is under the jurisdiction of the Grey Sauble Conservation Authority. Portions of the area directly to the north and to the south of the existing Lagoons are designated as Regulated Areas by the Authority Surrounding Land Uses The surrounding land use to the north of the study area are primarily residential. This area is entirely within the Niagara Escarpment Development Control area. Areas to the south and east of the study area consist of agricultural lands and are partially within the Escarpment Development area. A portion of the lands are zoned as A1 General Rural zoning. The lands directly west to the study area are agricultural lands, with a commercially zoned area beyond that, adjacent to Highway 6. Land to the west is also partially within the Escarpment Development area with an A1 General Rural zoning Archaeological Assessment Stage 1 and Stage 2 Archaeological Assessments were conducted as part of the Class EA process. The objective of the Stage 1 archaeological assessment was to evaluate the Study Area s archaeological potential and to provide recommendations on whether further archaeological assessment was required. The Stage 1 archaeological assessment determined that only the northern portion of the study area has archaeological potential as the remainder of the study 13

21 area is disturbed. Therefore, a Stage 2 archaeological assessment was recommended for the northern portion of the study area. The Stage 2 assessment was completed by conducting a test pit survey at 5 m intervals of the northern portion of the study area. No archaeological resources were observed during the Stage 2 archaeological assessment and no archaeological sites were identified within the study area. The recommendation arising from the Stage 2 assessment was that the study area be considered free of further archaeological concern and that no further archaeological assessment of the study area is necessary. The archaeological assessment was conducted in consultation with the Saugeen Ojibway Nation First Nations (SON) and in line with their Archaeological Guidelines. Representatives of SON attended both the Stage 1 and Stage 2 field investigations. The Archaeological Assessment Report is provided in Appendix B. 14

22 4 Alternative Solutions Phase 2 of the Class EA process requires the consideration of alternative solutions or methods to address the problem or opportunity addressed in the problem statement. This section describes the alternative solutions considered and the screening and evaluation process used to select a preferred solution. 4.1 Pre-Screening of Alternative Solution Categories Phase 2 of the Class EA included a screening of categories of alternative solutions. These categories included the following: Do nothing The do nothing scenario provides a baseline against which the compare the other alternatives. Under this scenario, the Wiarton WWTP would remain the same, while new residential developments are constructed and occupied. Based on the per capita average daily flows for the past three years, the projected wastewater flow rate would almost double its approved capacity by Control of infiltration and inflow Infiltration and inflow refers to rainwater, snowmelt and ground water that enters the sewage system through a variety of means, including pipe cracks, joints, manhole covers and drainage connections from private property. As sewage systems age, inflow and infiltration can increase due to worsening pipe and joint conditions. Infiltration and inflow can be reduced by replacing portions of the sanitary sewage collection system and disconnecting private property drainage systems. This matter is being looked in to by the Town separately. Provide additional wastewater treatment capacity New plant infrastructure could be added to or used to replace the existing WWTP. This may include upgrading the plant or building a new facility. These categories of alternative solutions were pre-screened against the problem statement to assess whether they were reasonable or feasible to carry forward. Table 2 provides a summary of the pre-screening results. Based on the results of the pre-screening, the category of adding additional treatment capacity was carried forward, as it was the only category that would be able to fully address the problem statement. 15

23 Table 2: Pre-screening of Alternative Solution Categories Category Do Nothing Will solution allow facility to increase its capacity? No. WWTP would exceed approved & design capacity with increased population growth. Will solution allow for an increased intake of septage? No. Will not allow for better handling of the septage and will have limited capacity to handle additional septage. Will solution allow facility to meet new federal ammonia standards? No. WWTP currently does not comply with new ammonia standard. Conclusion Do nothing would not allow WWTP to address problem statement. Control Infiltration/Inflow Additional Treatment Capacity No. Infiltration/inflow control measures may reduce wet weather inflow improving hydraulic load handling at the plant. However, it will not provide additional treatment capacity. Yes. Providing additional capacity through upgrades or replacement would allow WWTP to meet capacity requirements and adequately manage increased loads in wastewater contaminants. No. Will not impact septage handling and treatment in any way. Yes. The new treatment scheme can be designed to handle additional septage. No. Controlling inflow and infiltration would not have any impact on WWTP s ability to meet ammonia standards. Yes. Additional treatment would address new ammonia requirements. While Infiltration and inflow control measures would likely be beneficial and may improve the WWTP hydraulic loadings, it would only partially address the problem statement. Providing community with additional wastewater treatment capacity (either by upgrading the plant or replacing it) would address problem statement. 4.2 Identification of Alternative Solutions Three alternative solutions were identified for screening and evaluation. These are described below Alternative 1: Add Integrated Fixed-film System (IFS) with Nitrification Alternative 1 would see Wiarton s existing lagoon-based system reinforced by adding an Integrated Fixed-film System (IFS) with nitrification. In this approach, an IFS reactor (or tank) would be filled with small plastic carriers that increase microbial action in the tank by maximizing the surface area where the beneficial bacteria grow. The nitrification process would use bacteria to convert ammonia in the wastewater to nitrates. Treated wastewater leaving the IFS reactor would enter one of the existing lagoon cells, which could then be used as a settling tank and for sludge storage. The remaining cells could be converted to engineered wetlands to further treat the wastewater effluent. An optional denitrification ditch could be used to remove the nitrate from the wastewater effluent. The denitrification ditch would use a carbon source (e.g., woodchips) to convert nitrates to nitrogen. 16

24 The treated wastewater would then continue through the WWTP s existing UV/Filtration building before being discharged. Figure 5 illustrates this process. Figure 5: Alternative Solution 1 IFS with Nitrification IFS Settling Tank Wetland Wetland Wetland 2 ha 2 ha 2ha 2 ha BOD Removal Nitrification Woodchip Bioreactor Dynasand UV Disinfection outfall Alternative # 2: Deepen Lagoon Cell, with Nitrification Alternative 2 would see Wiarton s existing system reinforced by deepening one of the lagoon cells and adding nitrification. This would include: Deepening one of the cells and then creating two compartments within it. One compartment would be for BOD removal and the other for nitrification. Another cell would be used for settling solids and sludge storage. The third cell would be converted into an engineered wetland. The engineered wetland situated in the third cell would be developed in conjunction with borrow pit situated immediately south of the existing lagoons. The borrow pit is an area from which soil was excavated and used to build berms around the Plant s lagoons. As in Alternative 1, an optional denitrification ditch could be used to remove nitrates from the wastewater effluent. The denitrification ditch would use a carbon source (e.g., woodchips) to convert nitrates to nitrogen. The treated wastewater would then continue through the WWTP s existing UV/Filtration building before being discharged. Figure 6 illustrates this process. 17

25 Figure 6: Alternative Solution 2 Lagoon Deepening with Nitrification Aerated Lagoon Settling Tank Wetland Wetland 2 cells of 1 ha each 2 ha 2 ha 2 ha 3.5 meters deep BOD Removal Nitrification Woodchip Bioreactor (optional) Dynasand Sand Filter UV Disinfection Alternative #3: Conventional Activated Sludge Treatment This alternative would require the Plant to undergo considerable upgrading to convert from the existing lagoon-based facility to a conventional activated sludge facility. In this alternative, raw sewage would first undergo primary treatment as it enters the facility, including mechanical removal of grit and solids. The sifted sewage would then flow into a sedimentation tank, which would be modified from an existing cell. Solids would settle in the tank, and the liquid waste would flow on to the aeration cells. Pipe realignment, new valves and other engineering would be needed to modify the aeration cells. Two new aeration tanks would be installed to help speed up biodegradation of wastewater solids. The next cell would be converted into a secondary clarifier, where wastewater would be allowed to settle. Sludge removed from the wastewater (also called Waste Activated Sludge, or WAS) would be sent to a third cell for storage until it can be sent offsite for disposal or land application. Some sludge (called Return Activated Sludge, or RAS) from the secondary clarifier would be piped back into the first cell to inoculate new sewage entering the Plant. This would help activate the process. New piping and pumps would need to be installed for this return flow. As with the previous two alternatives, an optional denitrification ditch could be used to remove the nitrate from the wastewater effluent. The denitrification ditch would a carbon source (e.g., woodchips) to convert nitrate to nitrogen. The treated wastewater would then continue through the WWTP s existing UV/Filtration building before being discharged. Figure 7 illustrates this process. outfall 18

26 Figure 7: Alternative Solution 3 Activated Sludge Mechanical screens Grit tank Primary settling tank Activated sludge proces Secondary clarifier Sludge storage Woodchip Bioreactor (optional) Dynasand Sand Filter UV Disinfection outfall 4.3 Screening of Alternative Solutions Prior to the evaluation of the three alternative solutions, the alternatives were screening based on their various screening criteria relating to technical performance and costs. The screening criteria included: Hydraulic Loading: the flexibility of the alternative to accommodate variable flow rates, as the WWTP experiences widely variable flow rates. For example, in 2013 monthly average daily flow rates ranged between 1,125 m3/day to 3,608 m3/day, with a maximum peak day of 11,158 m3/day. Pre-treatment: the amount of pre-treatment required for the effluent before entering the treatment process. Sludge Production: the amount of sludge produced by the process, which would require further treatment and management, such as disposal in landfill or land application. Sludge Recirculation: whether recirculation of sludge is required for the treatment process (a portion of the sludge would be put back into cell 1 in order to inoculate the system with the beneficial bacteria). Resistance to Temperature Fluctuations: the ability of the technology to function in a range of temperatures. For example, in 2013 temperatures in Wiarton ranged from a high of 31 o C to a low of -24 o C. Capital Cost: The cost to build/install the system. Operating cost: The annual cost to operate the system. Table 3 compares the three solutions against the screening criteria. Based on the results of the screening, the IFS system and the lagoon modification alternatives were carried forward, while the activated sludge alternative was screened out. 19

27 Table 3: Alternative Solutions Screening Results Integrated Fixed-film System, with nitrification Deepening of Lagoon, with nitrification Activated Sludge Hydraulic Loading Flexibility High Alternative allows for flexibility with respect to hydraulic loading and would allow for fluctuations due to wet weather events High Alternative allows for flexibility with respect to hydraulic loading and would allow for fluctuations due to wet weather events Low Alternative is not very flexible and would require additional operational measures to respond to high flow events due to wet weather Pre-treatment Moderate Would require fine screening and a grit chamber None required Moderate May require optional screens and a grit chamber Sludge Production Low Low High Process would result in low volume of sludge production Process would result in low volume of sludge production Process would result in relatively high volume of sludge production Sludge Recirculation Not required Not required Required Resistance to Temperature Fluctuations Moderate Process would have good resistance to temperature variations Low Process would require protection from low temperature High Process would have high resistance to temperature variations, protection would not be required Capital Cost Low Low High Relatively less operating cost Relatively less operating cost Relatively more operating cost Operating cost Medium Medium High $4M to $5M $3.5M to $4.5M $5M to $6M Carry forward? Yes. Alternative provides reasonable approach to treatment Yes. Alternative provides reasonable approach to treatment No. Alternative has a number of disadvantages to other alternatives, in particular lack of flexibility with respect to hydraulic loading, sludge production, and operating/capital costs. 20

28 4.4 Evaluation of Screened Alternatives Evaluation Criteria Criteria Technical A set of technical, environmental, social/cultural, and financial evaluation criteria were developed to evaluate the alternative solutions. Table 4 presents a summary of the evaluation criteria. Ability to meet effluent quality objectives Table 4: Alternative Solution Evaluation Criteria Definition Whether the solution is able to meet the effluent quality objectives in the ECA, as well as the new federal standard for ammonia and any other considerations noted by MOECC Impacts on existing operations The degree to which existing wastewater treatment operations will be impacted during the construction of the solution Ease of implementation Flexibility to meet long-term objectives Maintainability of plant equipment and processes Ease of operation Natural Environment Impact on aquatic resources Impact on terrestrial environment, such as woodlots, parks or habitats Social/Cultural Land availability Archaeological Financial Capital costs Operating and maintenance costs Whether implementation of the solution will be relatively straight-forward or will be technologically complex The ability of the solution to meet the community s long term growth and effluent objectives The relative level of effort required to maintain plant equipment and processes of the solution The relative level of effort required to operate the solution The potential impact of the solution on aquatic resources The potential impact of the solution on the terrestrial environment The availability of land required for the solution The potential impact of the solution on archaeological resources The estimated capital cost of the solution The estimated annual operating and maintenance costs of the solution 21

29 4.4.2 Preferred Alternative Solution Alternatives 1 and 2 were evaluated against the evaluation criteria described above. Tables 5 to 8 summarize the results of the evaluation. The evaluation identified Alternative 1: IFS with Nitrification as the preferred alternative solution, based on the following rationale: Alternative 1 is best able to meet effluent quality objectives (i.e., discharge a cleaner effluent), which is a key criterion. This will provide the greatest level of environmental protection for Wiarton s aquatic resources. Alternative 1 can be implemented easily and with no impact on the Plant s existing operation. This minimizes any possible disruption of municipal wastewater treatment. In addition to IFS with Nitrification, Inflow and Infiltration Control measures should also be implemented as part of the community s regular capital infrastructure upgrades. The preferred alternative was presented to the public and to agencies through Public Open Houses # 1 and #2. 22

30 Table 5: Evaluation against Technical Criteria Evaluation Criteria Ability to meet Effluent Quality Objectives Impacts on Existing Operations Ease of Implementation Flexibility to Meet Long Term Objectives Maintainability of Plant Equipment and Process Ease of Operation Alternative 1: MBBR with Nitrification Excellent Better effluent quality can be achieved more reliably Excellent No impact on existing operation is expected Excellent Alternative can be very easily implemented Good Can handle additional organic loading better Good Some maintenance of the MBBR required Good The process is easy to operate Alternative 2: Deep Lagoon with Nitrification Good Better effluent quality is achievable Good Moderate impacts expected due to deepening of the lagoon Good Some disruption in plant operation expected while deepening one lagoon. Good Can handle additional hydraulic loading better Excellent Little maintenance required Excellent Ranked highest in ease of operation Evaluation Summary Technical Alternative 1 is preferred from a technical perspective because it is better able to meet Effluent Quality objectives (resulting in cleaner effluent) and can be implemented easily with little impact to existing operations. 23

31 Table 6: Evaluation against Natural Environment Criteria Evaluation Criteria Alternative 1: IFS with Nitrification Alternative 2: Deep Lagoon with Nitrification Impact on Aquatic Resources Impact on Terrestrial Environment Excellent Will meet effluent standards most reliably Excellent No additional land required; therefore no impacts Good Will meet effluent standards reliably Excellent No additional land required; therefore no impacts Evaluation Summary Natural Environment Alternative 1 is preferred in this category as it is best able to meet effluent standards, thereby minimizing risk to aquatic resources. Table 7: Evaluation against Social/Cultural Criteria Evaluation Criteria Alternative 1: IFS with Nitrification Alternative 2: Deep Lagoon with Nitrification Land Availability Archaeological Excellent No additional property required Excellent Archeological review indicates no potential for impacts Excellent No additional property required Excellent Archeological review indicates no potential for impacts Evaluation Summary Social/Cultural Both alternatives are equally is preferred in this category. 24

32 Table 8: Evaluation against Financial Criteria Evaluation Criteria Alternative 1: IFS with Nitrification Alternative 2: Deep Lagoon with Nitrification Capital Cost Good $4M to $5M Excellent $3M to $4M Annual Cost Operating Excellent Approx. $300,000 Excellent Approx. $300,000 Evaluation Summary Financial Alternative 2 is preferred in this category, as the capital costs are lower than in Alternative 1. The estimated operating costs are similar for both alternatives. 25

33 5 Phase 3 - Alternative Designs Phase 3 of the Class EA process requires the consideration of alternative designs for the preferred solution to resolve the problem identified in Phase 1. This section describes the alternative designs considered and the evaluation process used to select a preferred solution. 5.1 Review of Alternative Designs Three alternative designs were prepared for the implementation of the Phase 2 preferred solution. The alternative designs considered alternative layouts for the preferred design are discussed below Alternative Design #1 In Alternative Design #1, the proposed pre-treatment building and IFS tanks would be located by the existing Cell 1. This would result in the wastewater flow orientation being reversed. Figure 8 illustrates this alternative design. The characteristics of this alternative include: Wastewater would be transported by forcemain to the pre-treatment building and then the IFS tanks, near the existing Cell 1. A structure would be required to house the pretreatment facilities and the IFS tanks. The design also includes a new septage receiving station to receive deliveries of septage. The septage station would allow for the tracking of incoming septage. After treatment in the IFS tanks, the wastewater would then flow by gravity to Cell 3, which would be converted into an aerated lagoon. While the blower building would remain as is and continue to pump the air required for aeration, new piping would be required to connect the blowers to the converted Cell 3. The current Cell 2 would be divided in half. One half would become a settling lagoon, where solids would settle out from the treated water received from the aerated lagoon. The other half would be converted into an engineered wetland that would further treat the effluent. The current Cell 1 and the borrow pit to the south would be converted to an engineered wetland, for additional effluent treatment. A denitrification ditch could be installed to assist with reduction of nitrates in the treated effluent. The denitrification ditch would use a carbon source such as woodchips to convert the nitrates to nitrogen. This is an optional, value-added design feature. The treated wastewater would then flow by gravity from wetland through denitrification ditch to the existing filtration/uv building. Here, the effluent would be filtered using a sand filter and then treated with ultra-violet disinfection before draining to the outfall. 26

34 Figure 8: Alternative Design # Alternative Design #2 In Alternative Design #2, the proposed pre-treatment building and the IFS Tanks would be located by the UV/Filtration Building. Like Alternative Design #1, the flow orientation would be reversed compared to the existing Plant. Figure 9 illustrates this alternative design. The characteristics of this alternative include: The main difference between Alternatives Designs #1 and #2 are that the UV/filtration structure would be expanded to house the pre-treatment screens, the degritter and the IFS tanks. All of the facilities in a single structure should assist with the day to day operations and maintenance of the Plant. Wastewater would be transported by forcemain to the pre-treatment building and then the IFS tanks, located adjacent to the existing UV/filtration building. A structure would be required to house the pre-treatment facilities and the IFS tanks. The design also includes a new septage receiving station to receive deliveries of septage. The septage station would allow for the tracking of incoming septage. After treatment in the IFS tanks; the wastewater would then flow by gravity to Cell 3, which would be converted into an aerated lagoon. While the blower building would remain as is and continue to pump the air required for aeration, new piping would be required to connect the blowers to the converted Cell 3. The current Cell 2 would be divided in half. One half would become a settling lagoon, where solids would settle out from the treated water received from the aerated lagoon. The other half would be converted into an engineered wetland that would further treat the effluent. 27

35 The current Cell 1 and the borrow pit to the south would be converted to an engineered wetland, for additional effluent treatment. A denitrification ditch could be installed to assist with reduction of nitrates in the treated effluent. The denitrification ditch would use a carbon source such as woodchips to convert the nitrates to nitrogen. This is an optional, value-added design feature. The treated wastewater would then flow by gravity from wetland through denitrification ditch to the existing filtration/uv building. Here, the effluent would be filtered using a sand filter and then treated with ultra-violet disinfection before draining to the outfall. Figure 9: Alternative Design # Alternative Design #3 In Alternative Design #3, the proposed pre-treatment building and IFS tanks would be located by the UV/Filtration Building, as in Alternative Design #2. However, the flow of wastewater through the Plant would keep the same orientation as the existing facility. Figure 10 illustrates this alternative design. The characteristics of this alternative include: Like Alternatives Design #2, the UV/filtration structure would be expanded to house the pre-treatment screens, the degritter and the IFS tanks. All of the facilities in a single structure should assist with the day to day operations and maintenance of the Plant. Wastewater would be transported by forcemain to the pre-treatment building and then the IFS tanks, located adjacent to the existing UV/filtration building. A structure would be required to house the pre-treatment facilities and the IFS tanks. The design also includes a new septage receiving station to receive deliveries of septage. The septage station would allow for the tracking of incoming septage. 28

36 Unlike Alternative Designs #1 and #2, wastewater would then flow by gravity from the IFS tanks to the existing Cell 1, which would remain operating as an aerated lagoon. The blower building and piping from the blower building to Cell 1 would remain. The current Cell 2 would be divided in half. One half would become a settling lagoon, where solids would settle out from the treated water received from the aerated lagoon. The other half would be converted into an engineered wetland that would further treat the effluent. The current Cell 3 and the borrow pit to the south of Cell 1 would be converted to engineered wetlands, for additional effluent treatment. Treated wastewater would flow by gravity via a transfer pipe from the wetland constructed in Cell 3 to the wetland constructed in the borrow pit. A denitrification ditch could be installed to assist with reduction of nitrates in the treated effluent. The denitrification ditch would use a carbon source such as woodchips to convert the nitrates to nitrogen. This is an optional, value-added design feature. The treated wastewater would then flow by gravity from wetland constructed in the borrow pit through denitrification ditch to the existing filtration/uv building. Here, the effluent would be filtered using a sand filter and then treated with ultra-violet disinfection before draining to the outfall. Figure 10: Alternative Design #3 29