WATER TREATMENT PLANT AND INTAKE IMPROVEMENTS
Pierre, South Dakota
High Manganese Levels Prompt Centralized Water Treatment Plant
Currently, Pierre’s drinking water is obtained from a series of groundwater wells located throughout the city. Water is treated at each wellhead and pumped to storage tanks throughout the community.
In 2017, the City of Pierre began looking into treated water options following a community survey. The results show most respondents thought the City should consider constructing a water treatment facility to combat the high mineral content found in the City’s water supply. The manganese concentration was greater than 40 times the secondary standards recommended by the USEPA.
Project Details
Date: 2018 – Present
Client: City of Pierre
Key Project Elements
- Completed Facilities Plan with SDDENR
- New Water Source
- Pilot Study
- Membrane Filtration
- Public Relations
KT Analysis Helps the City Make the Right Decisions
Based on the results of a year-long comprehensive water system study conducted by AE2S, it was recommended the City build a $37 million membrane water treatment plant (WTP) just south of the Missouri River highway bridge.
To help identify other factors influencing the raw water source and WTP site location, AE2S worked with the City to conduct an extensive Kepner-Tregoe (KT) decision analysis. This process provided the City with a step-by-step approach that helped identify issues, analyze risks, and together with the capital costs, identify which alternative provided the City with the biggest “bang for their buck”. The recommended WTP site was on the edge of a city park, adjacent to the main highway.
In June 2018, the Pierre City Commission put the project to a public vote. Prior to the vote, the City retained AE2S to help conduct three public informational meetings to help convey the message to the City’s residents about the best solution for its long-term drinking water. The project passed with 73% of the vote.
Hydraulic Modeling
As a part of the comprehensive water system study, AE2S updated and calibrated the existing distribution system hydraulic model to perform operational analysis, as well as evaluate the preliminary design considerations for the addition of a new water treatment plant.
The model was used to plan system improvements for the next 30 years by projecting future populations and the corresponding water demands. The anticipated demands were then used to evaluate the adequacy of current storage and pumping capabilities and shortfalls were identified.
Pilot Study Helps Make Design Decisions and Maximize Operator Familiarity with Equipment
The City retained AE2S to conduct a membrane filtration pilot study and provide design services for the proposed WTP. The pilot study was used to evaluate the effectiveness of membranes to meet water quality goals, establish full-scale design and operating parameters, identify pretreatment requirements, determine fouling potential, estimate expected long-term performance, and help select equipment.
The pilot study provided multiple benefits for the City. In addition to the design details that were gained from the study, City staff were able to work with the equipment and membrane manufacturer suppliers and vendors to get a better understanding of what the full-scale operation of the membrane filtration equipment will require.
Design began in 2019 for the intake and membrane WTP. In July 2019, the City selected the Construction Manager at Risk (CMAR) firm of PKG-Scull to construct the intake and WTP. Construction is expected to begin in Spring 2020 and extend through May 2022.
