Dartmouth residents will once again see increases to their water and sewer bills in Fiscal Year 2026 as a part of a long-term plan to fund major infrastructure upgrades, cover rising project costs and maintain healthy reserves for future borrowing.

At its Tuesday, June 24 meeting, the Board of Public Works approved new utility rates to take effect July 1. Water rates will increase by 7.5% for those served by Dartmouth’s water system, while sewer rates will again increase by 8.5%. Residents on New Bedford water or sewer lines through Dartmouth will also see hikes aligned with those systems — 8.6% for water and a 3% sewer increase.

Town officials say these hikes are necessary to keep pace with rising construction costs and prepare for critical infrastructure improvements.

“We will definitely revisit this every year,” said Public Works Director Tim Barber. “With a lot of these large multi-unit developments coming online, with the increase in flows, BOD, sludge — there's a lot of increases coming in which eventually, I think, is going to push our 80% capacity a lot sooner than we had expected.”

The rates were developed with guidance from consultants Weston & Sampson and the Abrahams Group, who analyzed Dartmouth’s capital plans, revenues and borrowing needs to propose increases aimed at preserving 50% in retained earnings — a goal meant to keep the town financially stable while supporting ongoing and future work.

Public Works Board member Ronald Labelle voiced concern about project costs having already jumped substantially between fiscal years 2024 and 2025. “We have seen a significant increase … on project costs versus estimated costs,” he said. “We want to make sure numbers are as accurate as possible to avoid spiking when designed and put out to bid.”

However, financial challenges such as inflation have already been considered when developing the five- to 10-year capital plans for both water and sewer, according to the consulting groups.

Some of the major water projects planned over the next 5-10 years and their estimated cost:

• Route 6 water main replacement – $2 million
• Treatment plant clearwell/storage tank (687) – $2.8 million
• Raw water main improvements – nearly $3 million across two projects
• Treatment plant clearwell/storage tank (299) – $4.3 million

On the sewer side, the town is planning:

• Water Pollution Control Facility upgrade evaluation – $400,000
• Construction for WPCF upgrade – $50 million by FY28
• Pump station upgrades for large 40B housing project known as The Preserve – $160,000
• Brush grinder – $700,000

To fund those projects, the board approved last year a plan to increase sewer rates by 8.5% annually for six years, then potentially reduce increases to 4% annually once capital reserves are built up.

“Once we build that capital for us and we can work with our design and in construction on the plant, we can look at reducing that rate back down,” Barber said.

A $250,000 project focused on PFAS treatment upgrades may also be pushed back due to findings so far showing little contamination in Dartmouth. Further samples will be taken before a decision is officially made.