VILLAGE OF CASSELMAN CASSELMAN WASTEWATER TREATMENT SYSTEM MUNICIPAL CLASS ENVIRONMENTAL ASSESSMENT PHASE 2 REPORT (DRAFT) DRAFT AUGUST 8, 2017

Transcription

1 VILLAGE OF CASSELMAN CASSELMAN WASTEWATER TREATMENT SYSTEM MUNICIPAL CLASS ENVIRONMENTAL ASSESSMENT PHASE 2 REPORT (DRAFT) DRAFT AUGUST 8, 2017 Prepared for: VILLAGE OF CASSELMAN 751 St-Jean Street PO Box 710 Casselman, ON K0A 1M0 Prepared by: J.L. RICHARDS & ASSOCIATES LIMITED 864 Lady Ellen Place Ottawa, ON K1Z 5M2 JLR 27280

2 VILLAGE OF CASSELMAN CASSELMAN WASTEWATER TREATMENT SYSTEM MUNICIPAL CLASS ENVIRONMENTAL ASSESSMENT PHASE 2 REPORT - TABLE OF CONTENTS INTRODUCTION Background Class Environmental Assessment Process Objectives of the Class EA SUMMARY OF PHASE 1 FINDINGS Key Findings Phase 1 Problem and Opportunity Statement PUBLIC AND AGENCY CONSULTATION UPDATED SPECIALIZED STUDIES Receiving Water Assessment and Effluent Quality Requirements IDENTIFICATION OF WASTEWATER TREATMENT ALTERNATIVES Evaluation and Selection Methodology Initial Screening of Alternatives Option 2D New Aeration Cells Detailed Evaluation of Screened Wastewater Treatment Alternatives Option 2B Increasing the Depth of the Post-Aeration Cell Option 2C Add Baffles to the Primary Lagoon Cells Option 3 New specialized treatment system and existing discharge windows Option 4 New specialized treatment system and new discharge windows Option 5 New Mechanical Treatment Plant Opinion of Probable Costs of Screened Alternatives Capital, Operational and Lifecycle Evaluation Overview of Screened Alternatives...25 DRAFT August 8, 2017 i

3 VILLAGE OF CASSELMAN CASSELMAN WASTEWATER TREATMENT SYSTEM MUNICIPAL CLASS ENVIRONMENTAL ASSESSMENT PHASE 2 REPORT 6.0 PREFERRED SOLUTION COMPLETION OF PHASE 2 ACTIVITIES REFERENCES FIGURES - Figure 1-1 Casselman Municipal Class EA Location Plan... 2 Figure 1-2 Communal Wastewater System Overview... 3 Figure 1-3 Municipal Class EA Process... 6 Figure 5-1 Option 2D New Aeration Cells TABLES - Table 4.1: Receiving Water Classifications for Key Parameters...12 Table 4.2: Existing Effluent Compliance Limits (C of A No RVNRB)...12 Table 4.3: Proposed Effluent Limits...13 Table 5.1: Description and Preliminary Evaluation of Wastewater Treatment Alternatives...15 Table 5.2: Opinion of Probable Cost for New Aeration Cells...18 Table 5.3: Review of Specialized Treatment Systems...23 Table 5.4: Estimated Capital Cost of Wastewater Treatment Alternatives...24 Table 5.5: Estimated Operational Cost of Wastewater Treatment Alternatives...25 Table 5.6: Estimated Lifecycle Capital Costs of Main SPS and Lagoon...25 Table 5.7: Evaluation Impact Level and Scoring System...26 Table 5.8: Summary of Detailed Evaluation of Screened Alternatives...26 Table 5.9: Detailed Evaluation of Screened Alternatives...27 Table 6.1: Opinion of Probable Cost of Preferred Solution...31 DRAFT August 8, 2017 ii

4 VILLAGE OF CASSELMAN CASSELMAN WASTEWATER TREATMENT SYSTEM MUNICIPAL CLASS ENVIRONMENTAL ASSESSMENT PHASE 2 REPORT - APPENDICES - Appendix A Public and Agency Consultation Summary Appendix B Figures of Screened Alternatives Appendix C Conceptual Layout of Preferred Solution Appendix D Receiving Water Assessment DRAFT August 8, 2017 iii

5 VILLAGE OF CASSELMAN CASSELMAN WASTEWATER TREATMENT SYSTEM MUNICIPAL CLASS ENVIRONMENTAL ASSESSMENT PHASE 2 REPORT 1.0 INTRODUCTION 1.1 Background The Village of Casselman (the Village) initiated a Class Environmental Assessment (Class EA) of their wastewater treatment system in July 2016 to address various operational challenges (e.g. discharge constraints due to allowable release windows and aeration equipment), various problems experienced with treatment (e.g. elevated ammonia concentrations in the treated effluent) and also to ensure that increased influent flows from future growth can be effectively accommodated. In order to fully define the problems and identify a preferred solution to address these issues, (JLR) was retained by the Village to assist in the completion of the Class EA. The Village of Casselman (the Village) is located along the South Nation River in the United Counties of Prescott and Russell. The Village is located approximately 25 km east of the City of Ottawa just off Highway 417. The majority of the Village is serviced by a communal water supply system and a communal wastewater system. Refer to Figure 1-1 for an overview of the Village and study location. The wastewater collection system is generally made up of several kilometers of gravity sewer, four small sub-area sewage pumping stations and a main larger capacity sewage pumping station through which all sewage generated in the Village is conveyed. Construction of a new sewage pumping station is currently underway to service areas located north of the South Nation River. The wastewater treatment system (currently rated for 2,110 m 3 /day) consists of a seasonally discharged lagoon based system (the lagoon) including three clay lined facultative treatment cells (Cells A, B and C) (Cell C is equipped with aeration) a continuous chemical feed system for phosphorous removal, a flow measurement system and a gravity outfall pipe into the South Nation River. Seasonal discharge of effluent from the lagoons is permitted within specified times during the fall and spring of each year. Refer to Figure 1-2 for an overview of the Village communal wastewater system. A Phase 1 Report was completed in January 2017 to evaluate and identify problems with the existing system. Phase 2 of the Class EA involves identifying and evaluating possible alternative solutions to the problems identified in Phase 1. A Receiving Water Assessment was also completed during Phase 2 in order to identify constraints related to the receiving stream. DRAFT August 8,

6 Figure 1-1 Casselman Municipal Class EA Location Plan DRAFT August 8,

7 Figure 1-2 Communal Wastewater System Overview DRAFT August 8,

8 1.2 Class Environmental Assessment Process The Ontario Environmental Assessment Act (Act) sets out a planning and decision-making process so that potential environmental effects are considered before a project begins. The purpose of the Act is to provide for the protection and conservation of the natural environment (R.S.O. 1990, c.e.18, s.2). The Municipal Class EA process is followed for common types of projects to streamline the review process while ensuring that the project meets the requirements of the Act. It involves detailed sitespecific information gathering and studies, as well as consultation with the public and stakeholder agencies. In 1987, the first Class EA document prepared by the Municipal Engineers Association (MEA) on behalf of Ontario Municipalities was approved under the Act. Updates and amendments were subsequently made in 1993, 2000, 2007, 2011 and This Class EA was initiated as a Schedule C project under the Class EA process. The schedule designation of a Class EA project is to be reviewed during each subsequent Phase of the Class EA process. The originally anticipated Schedule C project designation was reviewed based on the flow projections and constraints identified in Phase 1, as well as the draft preferred solution identified through the identification and evaluation of various alternatives as presented in this report. Based on a review of the schedule designations provided within the Municipal Class EA document (Municipal Class EA, 2015), the project has been determined to be a Schedule B activity. It is noted that the preferred solution will not require expanding the wastewater treatment system beyond the rated capacity and does not result in an increase to the total mass loading to the receiving water body as permitted by the existing Certificate of Approval (C of A). Rationale for proceeding with this Class EA project as a Schedule B activity was presented to and approved by the Ministry of the Environment and Climate Change (MOECC) (refer to Appendix A for supporting documentation). Projects categorized as Schedule B undertakings have the potential for significant environmental effects, and are required to follow Phase 1 and Phase 2 specified under the Municipal Class EA. This includes consultation with all parties that may potentially be affected by the project, and the preparation of a Class EA Project File that documents the Class EA process for the project. DRAFT August 8,

9 The Class EA framework (refer to Figure 1-3) defines the process for each type of project. For Schedule B projects, the completion of the following Phases of the Class EA process are required: Phase 1 Identify the Problem and/or Opportunity Phase 2 Identify Alternative Solutions to the Problem and/or Opportunity The Project File shall be made available for public and agency review at the completion of Phase 2 of the Class EA process for a mandatory 30-day period. If there are no requests to the Ministry of the Environment and Climate Change (MOECC) for a Part II Order within this 30-day review period, then the project may proceed to implementation (Phase 5). 1.3 Objectives of the Class EA The objective of this Class EA is to identify the preferred servicing option for 10- and 20-year planning periods for the Village s communal wastewater system. The focus of this Class EA is the wastewater treatment lagoon, main pumping station and the forcemain to the lagoon although the rest of the collection system will be generally considered. The purpose of this Report is to summarize the results of Phase 2 of the Class EA process, including providing a review of the various options that have been considered to address the Problem Statement determined during Phase 1 and to recommend a preferred alternative. The Report objectives are to: Provide a brief summary of the problems and opportunities associated with the wastewater system identified in Phase 1. A detailed description of the sewage system and the problems associated with the system were presented in the Phase 1 Report (JLR, January 2017). Identify future wastewater system requirements to service the Village for the 10- and 20-year planning period. The Class EA process requires that the alternatives consider at least a 20-year planning period. The alternatives proposed should, therefore, be capable of accommodating projected sewage flows within this time period. Identify and evaluate possible alternative solutions to the problems in terms of economic consequences, overall feasibility, ability to address the problem, and the potential impacts on the surrounding environment. Provide a discussion of the alternatives and recommend a preferred alternative for consideration by the Village and other interested parties, including review agencies and the public. DRAFT August 8,

10 Figure 1-3 Municipal Class EA Process DRAFT August 8,

11 2.0 SUMMARY OF PHASE 1 FINDINGS 2.1 Key Findings The following are some of the key Phase 1 findings: The lagoon is located on Lots 7, 8, 9 and 10, Concession 6, in the Nation Municipality. The existing lagoon cells occupy most of the current site, with a vacant area of approximately 1.3 ha located in the south corner of the property. Immediately adjacent lands are not owned by the Village. The lagoon is constructed almost to the property boundary and the recommended 150 m buffer from sensitive land uses (MOECC, 1996) extends into neighbouring land. No other land use and natural environmental constraints were identified for the existing site. The geotechnical background information collected for the existing lagoon confirmed that three existing lagoon cells were constructed with a compacted clay cut-off through the full height of the berms to control leakage and seepage. In more recent years concerns have been raised by the Village regarding the condition of the lagoon berms. It is noted that based on a summary of lagoon influent and effluent flows presented in Technical Memorandum 2 (XCG, 2016) of the Phase 1 Report (JLR, 2017), there has not been a significant difference between the lagoon influent and effluent flows during the past three years. This observation suggests that it does not appear that significant leakage is occurring from the cells. However, the preferred solution should address berm erosion, provisions for the installation of erosion control measures such as rip rap, or other protective measures should be considered. The Casselman lagoon discharges to the South Nation River, which has been documented as a Policy 2 receiver with respect to phosphorous. Furthermore, the existing C of A requires the Village to apply dilution ratios during effluent discharge events that are based on water levels in the South Nation River. The influent quality to the lagoon has been relatively consistent in recent years and the concentration of TKN and TP fall within the range of literature values for low to medium strength raw municipal wastewater. It was noted, however, that the BOD 5 and TSS concentrations were not consistent with typical residential raw wastewater concentrations as a result of the location of the sampling point. As such, it has been recommended that typical values for medium wastewater strength be used for these parameters as the basis for this Class EA. Based on a review of the historical effluent quality, treatment has been within the C of A compliance requirements in all cases, with one exception in 2013 where the Total Ammonia limit was exceeded. In general, the effluent quality has been below the objectives for CBOD 5 DRAFT August 8,

12 and TP in both the fall and winter. In three of the years reviewed, the objectives for TSS were exceeded in either the spring or the fall. Exceedances of the total ammonia objectives are also common in the spring discharge period, and occurred in every year under review except for 2012 (as noted, in 2013 the limit was also exceeded). Operational challenges related to the lagoon allowable release windows, cell sizing and equipment have been confirmed. Considering the identified limitations and the projected design flows there is likely inadequate storage in the existing lagoon cell configuration. This issue may be exacerbated by high wet weather flows. Condition and capacity assessments of the main sewage pumping station (SPS) and associated forcemain identified various life-cycle upgrades that are to form part of the preferred solution. Upgrades to the SPS are to include a new mechanical bar screen, new PLC and wireless communications system, new UPS connected and monitored by the PLC, new exhaust fan starter, new sampling provisions for representative sampling of the raw wastewater and a new bypass overflow sewer to the South Nation River. An evaluation of potential growth in the service area was undertaken using an equivalent population approach. The population projections for servicing are 5,815 (year 2018), 6,618 (year 2028) and 7,546 (year 2038). Updated population and flow projections show that the currently approved theoretical rated capacity of the existing lagoon is not anticipated to be exceeded in the 10-year or 20-year design period projections. However, there are other factors currently limiting the actual operational capacity of the lagoon that will need to be addressed to ensure the community can be appropriately serviced over the design periods. 2.2 Phase 1 Problem and Opportunity Statement Based on the information developed and analyzed during Phase 1 of this Class EA, the following problem/opportunity statement was developed for the project: A review of Casselman Wastewater Treatment System suggests that there are operational constraints limiting the capacity of the lagoon as demonstrated by recent challenges in achieving effluent quality requirements. As a result, the Village of Casselman is undertaking a Class Environmental Assessment (Class EA) to evaluate options to upgrade the Casselman Wastewater Treatment System that consider current and future loadings to the lagoon, address operational issues related to achieving effluent quality limits, and ensure that the 10-year and 20-year community growth is adequately planned for and accommodated. The Class EA will consider the level and adequacy of wastewater treatment at the lagoon, and will DRAFT August 8,

13 recommend a solution to address the findings in accordance with the Municipal Class EA, 2015 process. 3.0 PUBLIC AND AGENCY CONSULTATION The Class EA process requires consultation with parties that may potentially be affected by the project. As part of Phase 2, the consultation plan developed in Phase 1 was followed in order to facilitate communication with the public and various agencies and other interested parties. Refer to Appendix A for the Phase 2 Public Consultation Summary and supporting documentation. Key components of Phase 2 Stakeholder consultation include: Reviewing the Public Consultation Plan (developed in Phase 1) Project Review Meetings Responding to Public Stakeholder Comments Responding to Review Agency Comments Maintaining Project Mailing List and Contacts Public Information Centre Key consultation correspondence from Phase 2 is included in Appendix A. A brief summary of some of the key results of this consultation is presented below: Ministry of the Environment and Climate Change (MOECC) - The MOECC provided initial feedback regarding the Class EA process at the onset of the project and was further consulted early on in Phase 2. A copy of the Phase 1 Report and Receiving Water Assessment was provided to the MOECC for review June 21, A meeting was held with the MOECC on July 4, 2017 to provide an overview of the project, review the current system constraints and discuss opportunities to increase the discharge windows to the winter months. Alternatives to be considered during Phase 2 of the project, including specialized treatment systems to improve ammonia were reviewed. The MOECC indicated that during the evaluation of options in Phase 2 and moving forward into preliminary design, consideration should be given to alternatives that can provide some incidental improvements in the treatment of TSS and cbod 5. Documentation of this correspondence with the MOECC is provided in Appendix A. Following the meeting, a letter was issued by JLR to the MOECC which provided a rationale to proceeding with the project as a Schedule B activity; it was noted that an increase to the rated capacity of the lagoon was not anticipated within the 20-year design period. An from Vicki Mitchell was received indicating that proceeding with the project as a Schedule B activity is a reasonable approach. DRAFT August 8,

14 A Council Meeting for the Village was held on July 11, At the meeting, JLR provided an overview of the project and identified the work completed during Phase 1 of the Class EA process. A preliminary list of alternatives to be considered during Phase 2 was reviewed. Council was also updated on the status of consultation with stakeholders. A copy of the presentation slides is provided in Appendix A. During the meeting, the Mayor indicated that the Township of Russel has recently upgraded its lagoon systems with aeration cells, and that the treatment systems were achieving their effluent quality objectives. A follow-up telephone conversation was held between the Mayor and Sarah Gore on July 12, 2017; it was noted during the call that JLR will be reviewing the Russell system and aeration cells in the context of this project. A note to file of the general items discussed is included in Appendix A. The Ministry of Natural Resources and Forestry (MNRF) The MNRF provided general information on the databases available. Natural heritage values were identified within the general study area, including a municipal drain, unevaluated wetland and raptor wintering area. Brook Stickleback was identified as a fish species present within the study area. The potential for Bobolink and Eastern Meadowlark (threatened species) was identified and it was noted that the area may be a suitable habitat for special concern species, including Monarch and Snapping Turtle. An ecological site assessment was recommended to identify the presence of any natural heritage features, any Species at Risk and/or their habitat. If Species at Risk are determined to be present onsite, permits/approvals would be required for any construction upgrades or site alterations. As such, an ecological site assessment is recommended to be completed during preliminary and/or detailed design of the proposed upgrades. Any necessary permits/approvals identified shall be obtained prior to on-site construction activities. A mandatory Public Information Centre (PIC) will be held in advance of finalizing this Phase 2 Report (August 24, 2017). The PIC will solicit additional input for consideration in establishing the final preferred alternative. 4.0 UPDATED SPECIALIZED STUDIES 4.1 Receiving Water Assessment and Effluent Quality Requirements A Receiving Water Assessment was completed to determine the constraints associated with expanding the allowable release windows and discharging to the South Nation River over the winter months (refer to Appendix D for the Technical Memorandum No. 3 Receiving Water Assessment). The Receiving Water Assessment includes a review of historic treated effluent from the Casselman lagoon, receiving water quantity/quality for the South Nation River, an evaluation of ambient conditions in the receiving water, an analysis of a modified discharge scenario (i.e., extending the discharge period to a semi-continuous feed) and mixing conditions within the DRAFT August 8,

15 South Nation River during specific months. Based on this information, the effluent discharge criteria for an upgraded, expanded discharge scenario for the wastewater treatment system were established. Two key reference documents for establishing receiving water quality criteria in Ontario are, Deriving Receiving-Water Based, Point-Source Effluent Requirements for Ontario Waters (MOE, July 1994a) and Water Management - Policies, Guidelines, Provincial Water Quality Objectives of the Ministry of Environment and Energy (MOE, July 1994b). The Provincial Water Quality Objectives (PWQOs) are guidelines for establishing acceptable water quality concentrations for various parameters. The above-noted policies classify receiving waters into two types: Policy 1 - In areas that have better water quality than the PWQOs, water quality shall be maintained at or above the Objective (evaluated on a parameter by parameter basis). Policy 2 - Water quality that presently does not meet the PWQOs shall not be further degraded and all practical measures shall be undertaken to upgrade the water quality to the Objectives. This Receiving Water Assessment assesses historical water quality data to determine whether the receiving waters can be classified as a Policy 1 or Policy 2 receiver for the parameters considered. Table 4.1 provides a summary of the receiving water classifications for key parameters and Table 4.2 presents the current effluent compliance limits for the Casselman Lagoon. DRAFT August 8,

16 Table 4.1: Receiving Water Classifications for Key Parameters Parameter Total Phosphorous (TP) Temperature 1 ph 1 Un-Ionized Ammonia Carbonaceous Biochemical Oxygen Demand (CBOD 5 ) Dissolved Oxygen (DO) Total Suspended Solids (TSS) Hydrogen Sulphide (H 2 S) 1 South Nation River Policy 2: no additional assimilative capacity available. The temperature difference between the effluent discharge and the 75 th percentile temperature of the South Nation River does not exceed 10 C. The effluent discharge ph exceeded the PWQO in the fall of 2011 (average 8.7); no other exceedance of the PWQO reported. Policy 1: Assimilative capacity available. No PWQO (no increase to the effluent CBOD 5 proposed). The 25 th percentile dissolved oxygen concentration is below the PWQO for warm water biota in January, March and December. No PWQO (No increase to the effluent TSS proposed). No exceedance of the PWQO. 1. Based on effluent discharge sample from Annual Reports ( ). Table 4.2: Existing Effluent Compliance Limits (C of A No RVNRB) Spring Discharge Fall Discharge Effluent Parameter Seasonal Average Concentration (mg/l) Seasonal Loading (kg/season) Seasonal Average Concentration (mg/l) Seasonal Loading (kg/season) CBOD , ,015 TSS 25 12, ,691 TP TAN , ,338 H 2 S Not Detected - ph Seasonal Flow Volume 502,500 m 3 /season (Mar. 7 May 15) 267,650 m 3 /season (Oct. 1 Dec. 19) Although there is no PWQO for CBOD 5 or TSS, no change is proposed to the effluent discharge compliance limits or loading for these parameters. In addition, since the South Nation River is considered a Policy 2 receiver with respect to TP, no change to the effluent compliance limit has been proposed for this parameter. Table 4.3 presents the proposed effluent limits for the Casselman Lagoon, based on the analysis presented in the Receiving Water Assessment. DRAFT August 8,

17 Effluent Parameter Table 4.3: Proposed Effluent Limits Discharge (January 1 to May 15) Average Concentration (mg/l) Loading (kg/season) Discharge (October 1 to December 31) Average Loading Concentration (kg/season) (mg/l) CBOD , ,015 TSS 25 12, ,691 TP TAN Non-acutely lethal Non-acutely lethal H 2 S Not Detected - ph Seasonal Flow Volume 502,500 m 3 /period 267,650 m 3 /period Other considerations that were presented within Technical Memorandum No. 3 Receiving Water Assessment included the following: The total effective storage volume of the wastewater treatment system (WWTS) is limited by the minimum submergence required above the aerators. The effective storage volume of approximately 260,000 m 3 is able to accommodate the 20-year projected incoming flows during the summer storage period (May 16 to September 30) prior to starting the fall discharge in October; however, there is insufficient storage available to handle the 20-year projected incoming flows during the winter storage period (December 20 to March 6). In order to address the winter storage constraint, modification to the discharge window and removal of the requirement to discharge with an ice free cover is proposed. Start-up of a specialized treatment technology in support of growth of the nitrifying bacteria during warmer fall months will help promote a healthy biomass that can be sustained during the winter months (e.g., continuing to nitrify the wastewater) and that will be readily available to nitrify the wastewater during the spring. Without continuous discharge, start-up of the specialized treatment technology may be difficult early in the spring as the cold wastewater temperatures (e.g. ice cover until mid-april) may impede initial growth of the biomass. The effluent dilution ratio (river flowrate to effluent discharge rate) can be more appropriately controlled with continuous discharge as the flowrate of treated effluent to the South Nation River can be reduced overall. Due to existing operational issues (ice cover and ammonia levels); the current discharge period has averaged approximately 26 days in the spring and 16 days in the fall from 2011 to With a longer discharge window, the volume of treated effluent can be more appropriately controlled. DRAFT August 8,

18 Reduced flowrates over a longer discharge period would provide opportunities to optimize the specialized treatment technology and reduce environmental and financial impact by reducing the overall footprint required and increasing potential energy conservation through reduced equipment sizing. It was noted that there may be more stringent ph requirements than the current compliance limits to meet the influent design requirements for new treatment technologies. Maintaining a new range of ph (e.g. 6.8 to 7.8) may be required to meet certain specialized treatment technologies for nitrification and end-of-pipe ammonia requirements. 5.0 IDENTIFICATION OF WASTEWATER TREATMENT ALTERNATIVES 5.1 Evaluation and Selection Methodology The main objective of Phase 2 of a Class EA is to identify and evaluate possible alternative solutions to the problem(s) (and/or opportunities) identified in Phase 1. All reasonable potential solutions to the problem(s), including the Do Nothing option, are considered. Class EAs for wastewater projects generally result in the identification and review of a broad range of solutions. It is also important to note that the objective of Phase 2 is to focus on determining an overall generalized solution to the problem and not necessarily all of the intricate details which are typically further explored and developed during Phase 5 of a Schedule B Class EA referred to as Implementation (i.e., preliminary and detailed design stage). In order to facilitate the evaluation and selection of the preferred solutions during Phase 2, a transparent and logical three part assessment process was established. This process included: Initial screening of alternatives; Detailed evaluation of screened alternatives; and Selection of a preferred alternative. The first evaluation stage considers the overall feasibility of the potential solutions and identifies those alternatives that fully address the problem statement. This step ensures that unrealistic alternatives are not carried forward to a more detailed evaluation stage. Based on the initial screening, a detailed assessment of the short list of alternatives is conducted. Evaluation criteria were developed based on a review of the background information, experience on similar assessments and in consultation with Village staff. The evaluation was conducted using criterion in the following four major criteria categories: Natural Environment and Archaeology Engineering and Technical Considerations Social and Community Well Being DRAFT August 8,

19 Financial Impacts Once the detailed evaluation was completed, a recommended preferred alternative or alternative(s) was identified for presentation to stakeholders and to solicit input prior to finalizing a preferred alternative. 5.2 Initial Screening of Alternatives Several alternatives are presented in Table 5.1 along with a summary of the review carried out to support a recommendation to either carry the alternative forward for further evaluation or not. Table 5.1: Description and Preliminary Evaluation of Wastewater Treatment Alternatives Alternative Review/Recommendation Option 1: Do nothing 1) Do nothing Review: This option would have a negative effect on the environment as it does not improve the spring ammonia effluent issues experienced in past years. It also does not mitigate the operational challenges related to lagoon allowable release windows and existing aeration equipment. This option does not address the problem; however, it will be carried forward as a baseline option for comparison. Option 2: Optimize/Modify Current Lagoon 2A) Increasing the dimensions of the primary facultative cells 2B) Increasing the depth of the post-aeration cell Recommendation: Carry Forward, as a Baseline only. Review: Increasing the operating volume of the lagoon may help to alleviate part of the challenge associated with current discharge constraints by providing more storage. It is noted that MOECC Design Guidelines (MOECC, 2008) indicate that the maximum sewage depth in facultative lagoons should be 1.8 m; which is equal to the current depth of the primary lagoon cells with a freeboard of 0.7 m. Furthermore, the existing lagoon cells already occupy most of the current site; therefore, expanding the surface area is limited. Increasing the primary facultative cells will not address the issues associated with total suspended solids and ammonia treatment. Recommendation: Do not carry forward. Review: Modification to the aeration equipment could provide some additional operating volume within the aeration cell and in the primary cells upstream. As noted within the Phase 1 report, a minimum level above the aerators is maintained to protect the equipment from freezing during winter months. Nevertheless, increasing the lagoon volume alone will not address the issues associated with total suspended solids and ammonia treatment. Recommendation: Carry forward but only as an option to be considered in combination with other alternatives. DRAFT August 8,

20 Alternative Table 5.1: Description and Preliminary Evaluation of Wastewater Treatment Alternatives (Continued) 2C) Add baffles to the primary lagoon cells Alternative Review/Recommendation Review: The addition of baffles within the primary lagoon cells will not address all the identified problems on its own, but it should provide some additional treatment by improving lagoon retention time (i.e., prevents short circuiting). This alternative should only be considered in combination with other options. Recommendation: Carry forward but only as an option to be considered in combination with other alternatives. Review/Recommendation 2D) New aeration cells Review: The addition of two new primary aeration cells that would discharge into the existing facultative cells and subsequently into the existing post-aeration cell (e.g., similar to the lagoons located in the Township of Russell) does not address the limitations of the available Village owned land at the lagoon site. Although this option appears to address treatment and lagoon storage requirements, the existing lagoon cells already occupy most of the current site, and therefore, sufficient land is unavailable for the approximate size of the new aeration cells required. Adding additional aeration cells would require acquisition of significant agricultural land and would impact the buffer separation between adjacent land uses. Further details and justification for pre-screening this option are presented in Section Recommendation: Do not carry forward. Option 3: New Specialized Treatment System and Existing Discharge Windows 3) Install specialized treatment system and maintain existing discharge windows Review: With the advancement of specialized treatment technologies, more consistent and improved effluent quality can be maintained over longer periods including winter months. Specialized treatment technologies that can be implemented within Village owned lands have the potential to meet the proposed effluent criteria and address the ammonia effluent quality issue in the problem statement. However, this option does not address the hydraulic issues experienced due to storage constraints; maintaining the current discharge windows does not address the operational challenges in discharging the lagoon adequately in the fall prior to winter storage or the ice cover constraint. Recommendation: Carry forward but only as an option to be considered in combination with other alternatives (e.g. Option 2B and 2C). DRAFT August 8,

21 Alternative Table 5.1: Description and Preliminary Evaluation of Wastewater Treatment Alternatives (Continued) Option 2D New Aeration Cells A review of the possibility of altering the existing lagoon cells to operate as partial mix aerated cells was undertaken to determine whether effluent quality can be improved to meet the proposed effluent objectives for the spring and fall effluent discharge. As part of this review, an assessment of the Township of Russell Lagoon system was conducted as it has been achieving excellent effluent ammonia results during both the spring and fall discharge periods. The current configuration of the Russell Lagoon consists of five cells; two primary aerated cells with a total surface area of approximately 14.6 ha, two secondary facultative lagoon cells (similar to the existing Casselman primary cells) with a total surface area of approximately 15.3 ha, and an aerated storage cell with a surface area of approximately 6 ha. It is noted that the Russell Lagoon has a rated capacity of 2,650 m 3 /d, and had an average day flow of approximately 933 m 3 /d in Note that the design capacity being proposed for the Casselman WWTS is 1,890 m 3 /day, which is close to that of the Russell Lagoon. Review/Recommendation Option 4: New Specialized Treatment System and New Discharge Windows 4) Install specialized treatment system and operate within new discharge windows Option 5: New Mechanical Treatment Plant 5) Replace lagoon completely with a new mechanical treatment plant Review: With the advancement of specialized treatment technologies, more consistent and improved effluent quality can be maintained over longer periods including the winter months. Specialized treatment technologies that can be implemented within Village owned lands have the potential to meet the proposed effluent criteria and address the ammonia effluent quality issue in the problem statement. This option can also address the hydraulic issues experienced by allowing increased flexibility to discharge treated effluent over the winter months thereby reducing the amount of total effective storage required within the 20-year period. Recommendation: Carry forward. Review: This option has the proven ability to meet the current effluent criteria and address the key issues in the problem statement; however, the costs are anticipated to be much higher than the other options and significant changes to the site and operations would be required. Costs are estimated to be $15M to $20M with annual operating costs in the $750,000 range. Nevertheless, the option has been carried forward as it can improve effluent quality, mitigate operational challenges and be implemented within the existing site constraints. Recommendation: Carry forward. DRAFT August 8,

22 The total surface area of the aerated cells within the Russell Lagoon (approximately 20.6 ha) is approximately 15.6 ha larger than the existing post-aeration cell (approximately 5 ha) of the Casselman WWTS. It is estimated that the additional aeration cell area required at the Casselman WWTS would be approximately 12.4 ha or two additional aeration cells of approximately 6.2 ha each. For illustrative purposes, Figure 5-1 shows the difference in the size of the existing Russell Lagoon compared with the Casselman WWTS and presents the conceptual aeration cell surface area and approximate additional land required. It is noted that sufficient Village-owned land is unavailable for the approximate size of the new aeration cells required. Adding additional aeration cells would require significant purchase of agricultural land and would impact the buffer separation between adjacent land uses. Table 5.2 provides an Opinion of Probable Construction Costs (OPCC) and operational costs with a Class D (Indicative Estimate) level of accuracy for constructing two aeration cells to the south of the existing post-aeration cell on privately owned land. The OPCCs were developed based on previous capital costs from similar projects, past experience, and professional judgment. The OPCC does not include additional costs to enter into an agreement with landowners for the purchase of the required lands. Table 5.2: Opinion of Probable Cost for New Aeration Cells Type of Cost Cost (2017 $) Estimated Capital Cost $5,000,000 Estimated Operational Cost $150, Estimated operational cost includes for energy costs for aeration and pumping equipment as well as chemical costs for phosphorous removal. 2. Equipment replacement costs have not been included. 3. Costs to purchase the additional land required is not included. 4. Engineering and Contingency are not included in the above capital costs. 5. The estimated capital cost was determined using the 2005 capital cost of the 5 ha post-aeration cell (approximately $2M) and prorating based on the estimated size of the aeration cells required (12.4 ha total). No increase due to inflation was accounted for in the above capital cost as the budget presented provides an approximate order of magnitude cost. As noted previously, this option has not been carried forward due to the land constraints at the current lagoon site. DRAFT August 8,

23 Figure 5-1 Option 2D New Aeration Cells DRAFT August 8,

24 5.3 Detailed Evaluation of Screened Wastewater Treatment Alternatives A detailed evaluation of the alternatives carried forward is provided below. Each screened wastewater treatment alternative, with the exception of Option 2, was assigned a score based on its relative anticipated impact (positive or negative) to the established criteria. The alternatives carried forward from Option 2 were not assigned a score, as these alternatives are to be considered only as part of the other options (i.e., Option 3, 4 and/or 5). An estimate of the construction and operational costs was also established to determine the feasibility of each alternative based on Village financial constraints for the Casselman WWTS (see Table 5.4 and Table 5.5 below). Refer to Appendix B for a conceptual overview of each alternative Option 2B Increasing the Depth of the Post-Aeration Cell Two alternatives from Option 2 (i.e., Optimize/Modify Current Lagoon) were carried forward to be considered in combination with other alternatives. Option 2B would be required in combination with Option 3 (i.e., installing a specialized treatment system and maintaining the existing discharge windows) due to the additional effective lagoon storage needed to meet the winter storage requirements for the 20-year design period. As noted previously, deepening the post-aeration cells by itself will not address the issues associated with TSS and total ammonia nitrogen. Working within the post-aeration cell could be difficult as the wastewater treatment system needs to be maintained in operation during construction. This option would also impact existing infrastructure, and therefore, a part of the previous capital investment made for the system would be negated. Nevertheless, it is not anticipated that deepening the post-aeration cell would have significant impact on the natural environment as the majority of the work would be completed within the existing cell for this option. The MNRF did identify the potential for threatened species and species of concern on-site, and therefore, consideration during design and construction for protection of these species and their habitat, if present, would be required. This option is not expected to have any significant impact to the community Option 2C Add Baffles to the Primary Lagoon Cells Option 2C is the other alternative from Option 2 (i.e., Optimize/Modify Current Lagoon) that was carried forward to be considered in combination with other alternatives. Although the installation of baffles to the primary lagoon cells would not result in adequate treatment enhancement to address the issues associated with TSS and total ammonia nitrogen on its own, it could be considered in combination with Option 3 or Option 4. It is expected that the baffles would provide some additional treatment by increasing the retention time in the system by reducing short circuiting through the cells. Working within the primary cells could be challenging as the wastewater system needs to be maintained in operation during construction. This being said, it may be possible to isolate one of the primary cells for short duration during the summer once the cells have been emptied following DRAFT August 8,

25 the spring discharge period. Minimal impact to the environment is anticipated from the installation of baffles within the cells Option 3 New specialized treatment system and existing discharge windows Option 3 is based on providing a new specialized treatment system downstream of the postaeration cell and maintaining the existing discharge windows of the current C of A. Specialized treatment systems were reviewed as part of this Class EA to determine whether improved effluent quality (particularly ammonia) could be achieved within the existing discharge windows set by the current C of A and for new discharge windows that extend through the winter months. The two technologies that are being considered for the Casselman WWTS are the submerged attached growth reactor (SAGR ) process and the moving bed biofilm reactor (MBBR) process. The SAGR treatment technology is a patented process that uses an aggregate media bed to treat wastewater which flows through the cell to a collection chamber at one end. The cells are typically horizontal and aeration is provided through the floor of the SAGR to provide the aerobic conditions necessary for nitrification. Peat or mulch is added above the granular cell to protect the cell from freezing. The granular material provides a surface within the cell for the nitrifying bacteria to attach themselves and nitrify the wastewater. The MBBR process is a fully submerged biofilm technology that uses specially designed polyethylene carriers within an aerated reactor. The carriers provide surface area for the nitrifying bacteria and remain in constant movement within the reactor due to the bubbles produced from the aeration grid. A biofilm is produced on the carriers and this biofilm is regulated by collisions occurring within the tank which helps to maintain a healthy biomass. Each of these treatment technologies have been demonstrated to provide nitrification under cold weather conditions. Both treatment technologies have different advantages and disadvantages depending on the criteria being evaluated. Table 5.3 provides a review of the SAGR and MBBR treatment technologies. Due to the shorter discharge periods compared with Option 4, the specialized treatment system developed for Option 3 will need to be larger in order to achieve the same effluent quality due to the higher flowrates required to be treated by the system. In addition, in order to meet winter storage constraints, increasing the depth of the post-aeration cell would also be required, and therefore, some impact to the existing system is anticipated. Nevertheless, the specialized treatment system combined with increased storage would provide a high quality effluent and sufficient storage for the 20-year design period. DRAFT August 8,

26 5.3.4 Option 4 New specialized treatment system and new discharge windows Option 4 is based on providing a new specialized treatment system downstream of the postaeration cell and modifying the discharge windows to allow discharge during winter months. With the advancement of specialized treatment technologies, more consistent and improved effluent quality can be maintained over longer periods including winter months. The above-noted specialized treatment systems have been demonstrated to be effective during cold weather. Longer discharge periods would provide opportunities to optimize the specialized treatment technology and reduce environmental and economic impact by reducing the overall footprint required and increasing potential energy conservation through reduced equipment sizing. This option does not require an increase to the depth of the post-aeration cell because the winter storage constraints are mitigated by the ability to discharge effluent throughout the winter months. Another advantage of this option is that the effluent dilution ratio (river flowrate to effluent discharge rate) can be more appropriately controlled with continuous discharge as the flowrate of treated effluent to the South Nation River can be reduced overall. With a longer discharge window, the volume of treated effluent discharged can be more appropriately controlled. This option would provide a high quality effluent and sufficient storage for the 20-year design period Option 5 New Mechanical Treatment Plant Option 5 is to install a new mechanical treatment plant at the current lagoon site. A new mechanical treatment plant would comprise of a new building housed with various process equipment and tankage for treatment of the wastewater. The size of the treatment plant would depend on the type of treatment processes. Part of the existing lagoon system may be retained as a form of equalization storage; however, other sections of the lagoon would likely be decommissioned for this option. Mechanical treatment plants have significantly greater operation and maintenance requirements than lagoon systems. Although, a high quality effluent can be produced with mechanical treatment, the capital and operation costs may be prohibitive for the Village. An evaluation of the screened alternatives is provided in subsequent sections. DRAFT August 8,

27 Table 5.3: Review of Specialized Treatment Systems Criteria Submerged Attached Growth Reactor (SAGR) Fixed Film Biological Process (MBBR) Proven Cold Weather Installations POSITIVE: Numerous Canadian/ and cold weather installations, however, subject to extreme environmental conditions. POSITIVE: Numerous Canadian/ and cold weather installations, however, subject to extreme environmental conditions. Ability to Meet Effluent Criteria POSITIVE: High quality effluent will be produced that is better than the proposed effluent limits for all parameters. Ammonia will be in the range of <5 mg/l. NO IMPACT: Good quality effluent will be produced that can meet the proposed effluent limits for all parameters. Degree of Process Control NEGATIVE: Submerged attached growth reactors have a higher degree of control then a lagoon alone, however, process control is limited and the system may be slow to respond. POSITIVE: There are a number of factors that can be controlled in the fixed film biological process; however, the lagoon is still required for treatment. Ease of Operation POSITIVE: Limited operator input is required once established. NO IMPACT: Automated process that may require periodic operator input. Compatibility with Existing Site NEGATIVE: New relatively large cells are required. Pumping to or from the new cells may be required due to the hydraulic grade line and elevation of the gravity sewer outfall pipe. NEGATIVE: New tankage is required. Although the process requires minimal area, pumping to or from the new tankage may be required due to the hydraulic grade line and elevation of the gravity sewer outfall pipe. Opportunities for Future Expansion NEGATIVE: The number of process cells could be increased; however, the level of effort would be relatively high and additional land would be required. POSITIVE: If a treatment capacity increase is required the quantity of the media in the basin can be increased at a low cost without the need for additional basins. Impacts During Construction NO IMPACT: Construction is limited to a small footprint and impacts to the area during construction would cause minimal disruption. NO IMPACT: Construction is limited to a small footprint and impacts to the area during construction would cause minimal disruption. Compatibility with Surrounding Land Use Noise and Odour Effects during Operation NO IMPACT: Minimal footprint outside of the existing lagoon would be expected. POSITIVE: Noise and odour will be similar the current operations. May be minor odour improvements due to enhanced treatment. NO IMPACT: Minimal footprint outside of the existing lagoon would be expected. POSITIVE: Noise and odour will be similar the current operations. May be minor odour improvements due to enhanced treatment. DRAFT August 8,