Lincus, as a leading consulting firm in energy efficiency and decarbonization, works with customers to achieve energy efficiency and decarbonization through innovative, affordable, and reliable solutions.
This case study provides an overview of how Lincus, requested by the Utility Service Provider to assist San Bernardino Municipal Water District (SBMWD), identified energy-efficiency opportunities within SBMWD’s wastewater treatment plant.
Background: Project and Facility Details
San Bernardino Municipal Water District, located in Southern California, has a 33 MGD capacity secondary treatment water reclamation plant. The plant currently treats an average flow of approximately 15.56 MGD. This plant carries out primary and secondary treatment processes to meet the discharge standards specified in the National Pollutant Discharge Elimination Permit (NPDES). The influent into the plant first enters the bar screens and then through the aerated grit chamber where large solid debris are removed.
The flow is then split in between a large Claerator (Unit 1) and a small Claerator (Unit 2) for secondary treatment process. Aeration is provided by high speed turbo blowers for Unit 1 and positive displacement blower for Unit 2.
Table 1: Existing Blower Details
|
Facility |
Unit 1 Blowers | Unit 2 Blowers |
| Quantity | 5 | 2 |
| Blower Type | Turbo Blower | Positive Displacement |
| Power, hp (Each blower) | 350 | 750 |
Solution: Implemented Energy Efficiency Measure
Based on the site energy data collected from SBMWD and a detailed audit of their plant, Lincus developed an energy-efficiency plan to implement at the site. Lincus recommended multiple energy efficiency measures (EEM) such as Ammonia Based Aeration Control (ABAC) and Chemically Enhanced Primary Sedimentation (CEPS).
Chemically Enhanced Primary Sedimentation (CEPS) was implemented at SBMWD’s plant.
Measure Application Type (MAT):
Based on the CPUC disposition provided for this project, this measure was considered as Add On Equipment (AOE) MAT. The AOE component for this measure is the addition of a chemical polymer system that enhances the primary sedimentation and results in energy savings on the host equipment which are blowers in Unit 1 (Turboblowers) and Unit 2 (Existing positive displacement blowers).
Effective Useful Life (EUL)/Remaining Useful Life (RUL):
The actual EUL for the host equipment is 20 years for wastewater aeration blowers from CPUC EO approval.
The host equipment for Unit 1 is Highspeed Turboblowers and was installed in September 2021 with an EUL of 20 years. The CEPS project was fully installed and commissioned in September 2024. As such the EUL of the CEPS measure for Unit 1 is 17 years which is the remaining useful life of the Turboblowers.
For Unit 2, the RUL of blowers is considered 1/3 of the EUL of blowers (20 years) which is 6.7 years. As such, the EUL of Unit 2 CEPS measure is 6.7 years.
Baseline Equipment/System Operation:
The raw wastewater passes through the headworks, and the flow is split equally between Units 1 and 2. Unit 1 includes a circular primary clarifier which feeds into an aeration basin and two secondary clarifier units. The existing primary treatment system currently does not have any other advanced treatment processes in place. Based on the existing condition at the primary clarifiers, the recommendation was provided to the customer on the potential benefit by adding the CEPS to their primary clarification system.
Implemented Equipment/System Operation:
The existing primary clarifiers did not have any advanced treatment processes in place. As the third-party implementer, Lincus proposed to install a chemically enhanced primary sedimentation (CEPS) system in the primary clarifiers to reduce the aeration demand from the Plant’s blowers.
The CEPS system will decrease biological oxygen demand (BOD) and increase solids removal in the primary clarifiers, which in turn will result in less aeration requirements. The CEPS system will include a chemical dosing system that uses ferric polymers to aid in enhanced flocculation. The ferric polymer dosing is achieved through a combination of Ferric Chloride and anionic Polymer chemicals, which SBMWD has already installed at the facility. The dosing usually is coupled with a Chemical Oxygen Demand (COD) analyzer to automate the process. Unfortunately, SBMWD is unable to install a COD analyzer to control the amount of dosing based on the BOD entering the secondary aeration process.
The proposed revised scope is to manually adjust the dosing of anionic polymer and ferric chloride to address the maximum influent mass loading (BOD x flow rate). The Plant influent flow follows a typical diurnal profile. The dosing of the anionic polymer and ferric chloride can be set at static maximum flow rate which is able to address the BOD concentration level when the flow is at its peak.
The schematic below shows the proposed measure operation:
Figure 1: Schematic of Installed Measure Operation-Updated Scope of Work
Results: Overview of Savings, Incentives, and Simple Payback Period
The implementation of the CEPS EEM outlined above provides a total energy and peak demand savings of 1,300,001.2 kWh/year and 160.38 kW, respectively, which equates to an annual utility cost savings of $143,000.14.
The IOU measure cost to implement this measure is $87,175.89 which along with utility incentives of $69,740.72, puts the simple payback period at 0.12 years.
The incentives are $0.12/kWh and $150/kW with a partnership adder of $0.09/kWh. Incentives are capped at 80% of the Full measure costs for the Add-on-Equipment (AOE) measure type. The total utility cost savings are based on an average utility rate of $0.11/kWh which was found based on the billing analysis.
This project was completed between June 2021 and September 2024.
Table 2: Savings Summary
| Savings Summary | Project Totals-Chemically Enhanced Primary Sedimentation (CEPS) |
| Energy Savings | |
| Annual IOU Electricity Savings (kWh) | 1,300,001.2 |
| Annual Customer Electricity Savings (kWh) | 1,302,614.6 |
| IOU Peak Demand Savings (kW) | 160.38 |
| Customer Demand Savings (kW) | 160.70 |
| Total Utility Savings ($)1 | $143,000.14 |
| Water Savings (gallons) | 1,231,580.1 |
| Cost Summary | |
| Total Measure Cost ($)2 | $87,175.89 |
| Incentive ($)3 | $69,740.72 |
| Net Measure Cost ($) | $17,435.17 |
| Simple Payback (Years) | |
| Without Incentive | 0.61 |
| With Incentive | 0.12 |
1Based on average utility rate of $0.11/kWh using billing analysis
2 Total Measure Cost (also Full Measure Cost) is the total project cost which is applicable for AOE MAT
3 Incentive rate of $0.12/kWh and $150/kW, with a partnership adder of $0.09/kWh. Incentives are capped at 80% of Full-measure costs for AOE projects.
To implement this measure, SBMWD purchased equipment such as chemical polymers, chemical dosing system, piping, etc. In addition, site staff also spent labor hours to properly install and commission the CEPS measure. Commissioning steps included finding the proper polymer dosing.
Analysis: Post Measurement and Verification Data Analysis
Using the data collected from SBMWD’s Supervisory Control and Data Acquisition (SCADA), and lab results, Lincus was able to verify the post-install energy usage of the blowers and calculate the annual energy savings and peak demand reduction. Lincus collected data related to blowers (Flow, pressure, electrical readings (kW)), Plant Influent flow, lab data such as Biological Oxygen Demand (BOD), ammonia (NH3) etc. for a period of 1 month to verify the savings. The higher reduction in BOD from primary influent to secondary influent as a result of CEPS measure resulted in the energy savings.
Whether your facility is addressing changing wastewater regulations or requiring data measurement and verification, Lincus can help support cost-effective solutions. Contact us today to learn more about energy-saving upgrades and incentive strategy support.