In July 2020 the town office was alerted to possible contamination of the Elliott Spring. Here is the process we undertook to eliminate the bacteria presence in the water.
Test Results at bottom of page
2020 Testing: We took a water sample on 7/28. The sample confirmed bacteria presence with 29.5 MPN. We replaced the water line and chlorinated the spring box. We next tested the water on 8/12, and bacteria presence was confirmed, since the lab did not indicate the MPN count we tested the water on 8/25 for an MPN count. The count from the 8/25 test showed a 9.1 MPN. After 8/25 test, we formulated a plan to contain water and prevent infiltration (see Spring Restoration plan). We completed the restoration work in November and tested the water again on 11/10. The water results showed less than 1 MPN, which is the threshold for contamination. We did our final water test with the state laboratory, as it was indicated this would be the most cost-effective laboratory for continued testing.
Water Line: The water pipe which conveys water from the Spring Box to the trough by the road appeared damaged and was replaced in July. We used a single piece of ¾” black polyethylene pipe to replace the existing damaged line. We used the existing coupling at the spring box to attach the pipe. We connected a 100’ pipe and cut off the excess (about 30’).
Spring Box Construction: The spring box consists of three structures on top of one another placed over time. The oldest structure is a wooden box surrounding the spring. The next structure on top is a concrete poured box which has decayed considerably and has a crack that may allow surface water flow from the outside thereby possibly contaminating the spring. On top there is a more recent spring box that prevents contamination from entering from the top. This was installed after the spring was evaluated by Joe Upson and Skip Hoag many years ago (1988?).
Geology: The source of the spring is a channel filled with 1 inch rounded gravel carved out of a compact clay-rich till. The channel enters the spring box from the left-center at the back and presumably continues underground toward Whiteface Intervale to the North. It appears the channel is covered with slump material. It is unknown what has buried the channel further to the North or whether it is exposed at the surface. However because the spring has a good perennial flow, it is likely that the channel supplying the spring is overlain by permeable sand found in Whiteface Intervale. On the right side of the spring house and facing toward the hill away from the road is black organic matter and large rocks which might be a larger channel that has been infilled with boulders and wetland material. This channel does not seem to transmit any significant groundwater.
Spring Restoration Plan: The side of the spring box was excavated so that the till was exposed horizontally 2 to 3 feet from the spring. The edge of the spring box was sealed with clay after parts of the rotten underlying wooden spring box was removed. The crack in the older concrete box was filled with hydraulic cement. A non-contaminating plastic liner was installed around the spring box and extending out horizontally away such that the plastic was level on the ground and then extending about halfway up the recent cement spring box. The corner of the plastic was cut at a 45 degree angle to allow the plastic to lie flat against the box. The corners and edges of the plastic were sealed with clay and additional plastic was laid over the gaps made by cutting the plastic corners. In the back of the spring box plastic was installed covering the exposed gravel channel. Once all the sealing was done the spring box was encapsulated with fine sand which acts as a filter to precipitation. To prevent erosion ledge pack was added to cover the fine sand.
Management Plan: We have been adding chlorine bleach to the Spring Box and the outlet for the water pipe. We add between two and six ounces of bleach every 4-6 weeks. Once bleach is added, we wait and test the water to see that chlorine has been drained from the spring box and water pipe. It usually takes an hour for the chlorine to be absent. We are using this management to keep bacteria levels low, as we try to determine if bacteria presence and contamination is occurring at the Spring box site, or somewhere before the water gets to the site. We recommend boiling before consuming. Boil Advisory Information
6/2/22 - Verbal confirmation from lab that coliform bacteria was present. Negative for ecoli. (this was a pass fail test, so cannot provide bacteria level)