In an April 17 letter to the city, state officials raised questions about a draft report on the city’s troubled water system prepared by city consultants, the Dufresne Group, which recommended the city continue replacing its aging water pipes over time rather than making changes to reduce the system’s high pressure.
The pipe replacement alternative “does not address the remediation of high-pressure transient events or reduce areas with elevated pressure conditions; therefore, Alternative 3 (replacing pipe materials without reducing pressures in the high pressure zone) is equivalent to the ‘Do Nothing’ Alternative,” the state’s letter reads. “Further, inadequate technical justification and support has been provided for the selection of Alternative 3.”
The city water system’s permit to operate from the state required it to provide “a system wide hydraulic analysis and a system improvements plan and schedule for review and approval.” The Dufresne Group’s preliminary report was meant to satisfy that requirement, but does not appear to have done so at this point.
The letter was signed by Allison Murphy, an engineer in the Drinking Water and Groundwater Protection Division of the Vermont Department of Environmental Conservation. She and Dana Nagy, the state’s Community Operations Section Supervisor in the Drinking Water division, are scheduled to appear at the city council’s May 10 meeting, according to Nagy.
Nagy noted that Montpelier’s high water pressure, which approaches 200 pounds per square inch in some lower elevations of the city — more than double the state’s recommended maximum pressure — is an issue affecting several aspects of the water system and has led to numerous water line breaks and complaints to the state from water system users.
“We feel it is important to evaluate all the alternatives before they move forward,” he said. “We want to come up with a solution that is beneficial to the water system and all its users.”
The draft Dufresne report recommended Montpelier focus on replacing about half of its aging water pipes rather than taking steps to reduce the system’s water pressure. Replacing the pipes will cost $61.8 million, the report said, and would be necessary even if an estimated $19 million was spent on reducing water pressure.
“[A] large portion of the water system distribution network is approaching, or has exceeded, its expected useful lifespan,” the Dufresne report said. “It is estimated that approximately 11% of distribution mains have exceeded their expected useful lifespan while an additional 35% are expected to exceed their useful lifespan within the next 20 years.”
Water line breaks because of the age and condition of the pipes have been an ongoing issue in the city, as have damage to homes and businesses when high pressure and line repairs caused some pressure-reducing valves to fail.
The letter from the state includes an attachment with 52 specific questions for the city. Nagy said the state, which had a “cordial” meeting with the city on April 17, expects a response from Montpelier within the next one or two months. The April 28 Department of Public Works newsletter says the staff is working with the Dufresne Group to develop responses to the state comments ahead of the May 10 council meeting.
The newsletter also states that public comment on the report can be sent to DPW Director Kurt Motyka at kmotyka@montpelier-vt.org, or comments can be offered after the presentation at the city council meeting.
The full letter and attachments can be found at tinyurl.com/bdfkrmcn. Below is a sampling of the questions in the attachment.
Where are the services that experience normal operating pressures of 200 psi (location and number of them)?
How was it determined that the soils on East State Street, School Street, Gallison Hill Road, and Mechanic Street are corrosive? Was soils testing completed in these areas? What is the pressure class of pipe used in these areas?
Why were dedicated tank fill lines not considered? This strategy is used by other Vermont systems to limit subjecting users’ infrastructure to high pressures.
Water system users have reported concerns regarding transient events, including that their house shakes, internal and external property damages (e.g., boilers, landscaping), frequent service interruptions, displacement during severe events. Please expand upon Section 4.2 to explicitly talk about how users’ concerns have been addressed.
What is the estimated cost of a Boil Water Notice to the downtown high pressure zone? What about the schools served by the Water System?
The recommended alternative project does not include all water mains that need to be replaced, nor does it provide the reasons for phasing the improvements. Alternative 3 and Table 5-1 evaluate replacing approximately 140,000 linear feet of pipe; the recommended alternative lists less than 5,000 of linear feet of pipe … Please add the reasons for phasing the project to Section 6 and provide the proposed phasing in tables.
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