MIDDLEBURY — Around 300 Middlebury properties continue to be under a boil water notice caused by what town officials described as a major “surge” within the municipal water system that occurred late last month.

The surge, according to Middlebury Director of Public Works Planning Emmalee Cherington, “caused a high-pressure wave to travel through the system, causing breaks at weak points in the lines.” This resulted in 11 water main breaks (at last count), prompting public works staff to put in long hours to make repairs and restore water service.

Town staff are working with an engineering team to better understand and troubleshoot the problems to limit further damage to the water system, according to Cherington.

Those affected by the boil water area are include:

• From 1129 Route 7 (former U.S. Forest Service Ranger Station) to the Lower Foote Street intersection.

• All of Cady Road, which runs between Route 7 and Case Street.

• Maecliff Court.

• Most of Lower Foote Street (the part south of the farm to the intersection with Route 7).

• Case Street from Airport Road north to the north entrance of Mead Lane.

• Airport Road, Munson Road, North Ridge, Mead Lane, Drew Lane and the Lindale Mobile Home Park.

“There are still two known leaks that we are working to locate in the Case Street area of the system,” Cherington said on Monday. “Vermont Rural Water Association (staffers) are coming out to assist in that effort this week.”

It is unclear when the boil water notice will be lifted. State officials will determine when the town water system can be tested — a precursor to (hopefully) lifting the order, Cherington noted.

“They have requested that we test our 10 standard locations for the impacted properties on Wednesday in addition to three additional sites (likely to receive results on Thursday),” she said. “Updates will be posted to the (town) website as soon as we receive permission to lift the order.”

Town officials said people on the affected streets should not drink tap water before boiling it, because it could be contaminated through the leaks in the mains. Boiling kills bacteria. Boil water for one minute. Use boiled water or bottled water only — not tap water — for drinking, making ice, brushing teeth, washing dishes and preparing food, water department officials advised.

The current water issues, according to Cherington, aren’t related to last summer’s replacement of a large box culvert near Dow Pond that interrupted through-traffic along Route 116 for several weeks. That major project forced a lengthy boil water order for properties north from Jehovah’s Witness Church, Butternut Ridge, Mead Lane and Lindale Trailer Park.

Reporter John Flowers is at [email protected].