Dayton taps PFAS settlements for $1.7m Ottawa WTP construction oversight
City of Dayton Department of Water, Ohio · Meeting date: October 28, 2026 · Published: October 29, 2026
Dayton City Commission has approved a $1.7 million amendment with Tetra Tech for construction administration, full-time site representation and materials testing on the Ottawa Water Treatment Plant PFAS-treatment project. The work supports a dedicated facility intended to remove PFAS from finished water after several Mad River wellfield wells were shut down because of contamination.
Key points
- The $1.7 million second amendment lifts Tetra Tech’s total engineering agreement for Ottawa WTP advanced PFAS treatment to $14.85 million, with a term through December 2031.
- PFAS-manufacturer settlement proceeds will fund the amendment, while the original agreement and first amendment were funded through a 0% Ohio EPA loan.
- Tetra Tech will provide $1.3 million of construction administration, a $300,000 on-site resident project representative and a $100,000 allowance for special inspections and materials testing.
- The planned treatment system uses anion-exchange resin and is designed around 96mgd of prefiltration and PFAS treatment capacity in its first phase.
Full report
Dayton has moved its Ottawa Water Treatment Plant PFAS programme into its construction-support phase, approving a $1.7 million amendment with Tetra Tech funded by proceeds from the city’s claims against PFAS manufacturers.
The amendment covers construction administration, on-site inspection and special inspections and materials testing for the advanced PFAS-treatment project. It lifts Tetra Tech’s overall engineering agreement from $13.15 million to $14.85 million, with the contract running through December 2031.
The funding decision marks a shift in the programme’s financing. Dayton used a 0% loan from the Ohio EPA Division of Environmental and Financial Assistance for the original planning and preliminary-design agreement, as well as the subsequent final-design, permitting and regulatory-coordination amendment. The newly approved construction-phase services will instead be paid from PFAS settlement proceeds.
Ottawa WTP draws raw water from the Mad River wellfield, where Dayton has identified PFAS contamination through years of sampling. Several wells have been taken out of service, and the city said the project is intended to meet EPA requirements for PFAS in finished water and restore lost pumping capacity.
Tetra Tech’s construction-phase budget allocates $1.3 million to construction administration, $300,000 to a resident project representative and $100,000 to special inspections and materials testing. The resident representative is expected to conduct daily observations of construction activities, with an anticipated on-site commitment of 40 hours a week.
The consultant’s duties include reviewing up to 400 shop drawings and 250 requests for information, attending monthly progress meetings, making site visits across civil, process, mechanical, architectural, structural and electrical disciplines, and preparing record drawings and operating and maintenance manuals. The scope anticipates construction of the two project phases over 60 months.
Dayton selected anion-exchange resin for the full-scale PFAS facility after evaluating treatment alternatives. Phase 1 is planned to include a 96mgd transfer-pump wet well, underground reservoir, 16-bag prefiltration system and either 28 14ft-diameter or 24 15ft-diameter PFAS-treatment vessels. It also includes four 12mgd solids-contact clarifiers, providing 48mgd of softening capacity. A second phase is planned to add another four clarifiers and further reservoir storage.
Shook Construction holds a separate construction-manager-at-risk contract for the PFAS-treatment facility. The Tetra Tech amendment adds specialist oversight alongside inspection work performed by Dayton staff.
This summary was generated by AI based on the source document and may contain errors.
Source: City Commission, City of Dayton Department of Water