Lagoon Upgrade Project
Last Updated October 25, 2018
Background
The original Business Case for the lagoon system upgrade was presented to Alberta Transportation (AT) in November of 2013. The project was at the preliminary stage at that time. A more detailed application was submitted on November 22, 2015. This application was based on confirmation from Alberta Environment and Parks (AEP) on October 6, 2015, on the new performance requirements from the WRSSC lagoon system.
The project was found eligible under the terms of the AMWWP program. However, the project was placed on AT’s potential project list and the WRSSC was notified that funding for this project would be considered based on provincial priorities and budget availability.
In the spring of 2016, AEP requested the submittal of additional information related to the renewal of the WRSSC Lagoon System EPEA Approval. As such, MPE developed a revised Plan for Operating Approval. The Approval was renewed in October of 2016 for a period of ten years.
On September 21, 2017, MPE, on behalf of WRSSC, submitted an updated application for funding under the AMWWP program.
Effluent Requirements
Since the latest application to AEP, there have not been any changes in the expected effluent requirements. The effluent limits, as presented in the September 21, 2017 grant application update, remain.
Moreover, the original cost estimate was developed in 2015. An annual inflation factor of 2.5% per year for the period of 2015 to the start of 2019 is accounted for in this cost estimate.
Required Upgrades
Similar to the previous grant application, the latest lagoon performance requirements involve upgrades to the system to improve CBOD, TSS, Ammonia-Nitrogen, Total Phosphorus and Coliforms removal.
The project has not changed and includes the following upgrades:
Staging and Cost Estimate
The September 21, 2017 grant application provided an update to the previous cost estimate developed in 2015. An annual inflation factor of 2.5% per year for the period of 2015 to 2019 was accounted for in this cost estimate.
The upgrades required to achieve the new effluent limits are still proposed to take place in two stages.
Stage 1A
Stage 1B
Stage 2
Table 1 provides a summary of the projected cost. The detailed cost estimate is provided in Appendix A.
The original Business Case for the lagoon system upgrade was presented to Alberta Transportation (AT) in November of 2013. The project was at the preliminary stage at that time. A more detailed application was submitted on November 22, 2015. This application was based on confirmation from Alberta Environment and Parks (AEP) on October 6, 2015, on the new performance requirements from the WRSSC lagoon system.
The project was found eligible under the terms of the AMWWP program. However, the project was placed on AT’s potential project list and the WRSSC was notified that funding for this project would be considered based on provincial priorities and budget availability.
In the spring of 2016, AEP requested the submittal of additional information related to the renewal of the WRSSC Lagoon System EPEA Approval. As such, MPE developed a revised Plan for Operating Approval. The Approval was renewed in October of 2016 for a period of ten years.
On September 21, 2017, MPE, on behalf of WRSSC, submitted an updated application for funding under the AMWWP program.
Effluent Requirements
Since the latest application to AEP, there have not been any changes in the expected effluent requirements. The effluent limits, as presented in the September 21, 2017 grant application update, remain.
- CBOD ≤ 20 mg/L
- TSS ≤ 15 mg/L
- Ammonia-Nitrogen ≤ 6.4 mg/L (Winter), 5 mg/L (Summer)
- Total Nitrogen ≤ 15 mg/L
- Total Phosphorus ≤ 0.5 mg/L
- Total Coliforms ≤ 1,000 UFC / 100 mL
- Faecal Coliforms ≤ 200 UFC / 100 mL
Moreover, the original cost estimate was developed in 2015. An annual inflation factor of 2.5% per year for the period of 2015 to the start of 2019 is accounted for in this cost estimate.
Required Upgrades
Similar to the previous grant application, the latest lagoon performance requirements involve upgrades to the system to improve CBOD, TSS, Ammonia-Nitrogen, Total Phosphorus and Coliforms removal.
The project has not changed and includes the following upgrades:
- Upgrades to the Transfer Lift Station.
- Upgrades to the existing interconnecting piping.
- The addition of a third partial mix cell.
- The addition of a SAGR system (three cells) after the third partial mix cell.
- Upgrades and addition to the aeration system.
- The addition of a chemical injection system, including a chemical storage building following the SAGR system.
- The addition of a fine screen and UV disinfection system, including a utility building following the chemical injection system.
- The addition of a gravity effluent discharge piping system.
- The addition of a river diffuser system.
Staging and Cost Estimate
The September 21, 2017 grant application provided an update to the previous cost estimate developed in 2015. An annual inflation factor of 2.5% per year for the period of 2015 to 2019 was accounted for in this cost estimate.
The upgrades required to achieve the new effluent limits are still proposed to take place in two stages.
Stage 1A
- Upgrades to Transfer Lift Station.
- Addition of interconnecting piping to allow operating the existing Partial Mix Cell in series.
- Aeration System Upgrades – Replace the existing coarse bubble diffusers in the Complete Mix Cell and the two Partial Mix Cells with fine bubble diffusers. The new diffusers will allow for a more efficient transfer of oxygen; this will allow for better CBOD removal.
- SAGR System – Installation of a Submerged Attached Growth Reactor (SAGR) system
(2 of 3 cells) downstream of the Partial Mix Cells for removal of Total Ammonia. The SAGR may also be able to provide additional CBOD and TSS polishing, as well as disinfection. - Alum Injection – Installation of chemical injection system for the removal of Total Phosphorus from the system through precipitation in Cell 4 (polishing cell).
- Disc Filter – Phosphorus removal is anticipated to be achieved through Alum injection which will generate additional particles. Should additional removal be required to avoid carry over in the effluent, a disc filter would be installed. The disc filter would also aid in the removal of algae should it form in the summer months.
- River Diffuser – Installation of a multi-port diffuser in the Sheep River to allow for more efficient mixing of the effluent as it enters the river.
Stage 1B
- UV System – It is anticipated that the future system will be able to handle coliforms through the proposed Stage 1A processes. After two years of operation of the Stage 1A processes, it is recommended that an assessment be completed to determine if the approval requirements are being met or if additional disinfection is required. Should the coliform requirements not be met in the Stage 1A upgrades, a UV system would be installed.
Stage 2
- Partial Mix Cell – Construction of a third Partial Mix Cell with fine bubble aeration to allow for additional CBOD and TSS removal time.
- SAGR System – Installation of a third SAGR Cell for additional Total Ammonia removal for future flows.
Table 1 provides a summary of the projected cost. The detailed cost estimate is provided in Appendix A.
Table 1 – Cost Estimate
|
Description
General Requirements
Transfer Lift Station Upgrade
Upgrade Cells 1A, 1B, 2, 3A, 3B
New Partial Mix Cell 3C
New SAGR System Cell 3D1, 3D2, 3D3
Areation System All Cells & SAGR System
Chemical Storage Building (Alum)
Fine Screening & UV Disinfection
Outlet to Sheep River
Subtotal
ontingency (20 %)
Engineering (15%)
Third Part Testing (3% civil work)
Total (Rounded)
GRAND TOTAL
|
Stage 1A
$999,000
$540,000
$346,000
$42,000
$2,372,000
$2,217,000
$732,000
$1,258,000
$829,000
$9,335,000
$1,867,000
$1,680,000
$105,000
$12,990,000
|
Stage 1B
$26,000
-
-
-
-
-
-
$235,000
-
$261,000
$52,000
$47,000
-
$360,000
$18,220,000
|
Stage 2
$395,000
-
-
$1,096,000
$1,186,000
$791,000
-
-
-
$3,468,000
$694,000
$694,000
$82,000
$4,870,000
|
Current Lagoon Performance
The current EPEA Approval requires the CBOD to be less than 25 mg/L which is still achieved by the current system.
However, the current lagoon system performance does not meet the future limits.
Table 2 provides a summary of the current system performance and a comparison with the future limits.
The current EPEA Approval requires the CBOD to be less than 25 mg/L which is still achieved by the current system.
However, the current lagoon system performance does not meet the future limits.
Table 2 provides a summary of the current system performance and a comparison with the future limits.
Table 2 – System Performance
|
Parameters
CBOD
TSS
Ammonia-Nitrogen
Total Nitorgen
Total Phosphorus
Total Coliforms
Faecal Coliforms
|
Current System Limits
< 25 mg/L
N/A
N/A
N/A
N/A
N/A
N/A
|
Upgraded System Limits
< 20 mg/L
< 15 mg/L
< 6.4 mg/L, < 5 mg/L
< 15 mg/L
< 0.5 mg/L
< 1,000 UFC/100 mL
< 200 UFC/100 mL
|
Average Performance
2 to 18 mg/L
2 to 70 mg/L
13 to 70 mg/L
N/A
3 to 5.5 mg/L
13 to 8,000 UFC/100 mL
15 to 4,400 UFC/100 mL
|
Over the course of 2018 there were significant increases in the exceedances of the upgraded system limits as follows:
AEP confirmed that the current CBOD limit of 25 mg/L will continue to apply until the wastewater treatment is upgraded. The governing factor to meet the CBOD limit is the hydraulic retention time of the existing system. It is expected that by 2019 this parameter will be exceeded, which will then initiate all the new effluent limits set by AEP.
The proposed project schedule in Table 3 is based on the need to have the upgrades constructed and commissioned by 2020.
- The average system performance of Ammonia-Nitrogen increased from 35 mg/L to 70 mg/L over the course of 2018 (11 times the upgraded system limit).
- The average system performance of Total Coliforms spiked to 8,000 UFC/100mL over the course of 2018 (8 times the upgraded system limit).
- The average system performance of Feacal Coliforms spiked to 4,400 UFC/100mL over the course of 2018 (22 times the upgraded system limit).
AEP confirmed that the current CBOD limit of 25 mg/L will continue to apply until the wastewater treatment is upgraded. The governing factor to meet the CBOD limit is the hydraulic retention time of the existing system. It is expected that by 2019 this parameter will be exceeded, which will then initiate all the new effluent limits set by AEP.
The proposed project schedule in Table 3 is based on the need to have the upgrades constructed and commissioned by 2020.
Table 3 – Project Schedule
|
Description
Secure Funding
Preliminary Design
Detailed Design
Tender and Award
Construction
Project Commissioning
|
Time Frame
Spring 2019
Summer/Fall 2019
Fall 2019/Winter 2020
Winter/Spring 2020
Spring to Fall 2020
Fall 2020/Winter 2021
|
Closure
The lagoon system is currently facing the limit of its treatment capacity and is facing new effluent limits.
This project proposes to improve the lagoon system efficiency to meet a more stringent CBOD limit and new TSS, Ammonia-Nitrogen, Phosphorus and Coliform high quality limits. All the proposed upgrades are in light and in support of the Bow River Basin Phosphorus Management Plan.
Given the age of the facility and the timing of the current system capacity to meet the new effluent limits, the WRSSC is taking a proactive approach to the future development of the wastewater treatment facility.
The lagoon system is currently facing the limit of its treatment capacity and is facing new effluent limits.
This project proposes to improve the lagoon system efficiency to meet a more stringent CBOD limit and new TSS, Ammonia-Nitrogen, Phosphorus and Coliform high quality limits. All the proposed upgrades are in light and in support of the Bow River Basin Phosphorus Management Plan.
Given the age of the facility and the timing of the current system capacity to meet the new effluent limits, the WRSSC is taking a proactive approach to the future development of the wastewater treatment facility.
