Our Water System Explained (part two)
Well #1 – Off Norfolk Street in Stoddard Park
On a public lake and surrounded by houses, this well is not ideally situated. It does have elevated levels of magnesium. However, over the years it has continued to be a significant contributor to Holliston’s water supply.
Well #2 – On Maple Street, off Winter Street
This has been and remains another key production source. However, this well also suffers from a poor location -- resulting in three problems, which
the DEP is pressing the Water Department to remedy within the next 18 months.
Ground Water under the Influence of Surface Water Well #2 was built in 1948 near a stream. Several years ago during an unusually heavy rain, there was an indication that the well might have been contaminated with surface water. Increased testing was ordered by DEP. In 2008, two consecutive MPA tests showed a moderate risk of GUI. These tests resulted in DEP issuing a “Notice of Determination” to the Town, requiring remedial action within 18 months. The Town can abandon the site, modify the site with a replacement well ($0.5 – 1.0M), or build a water filtration plant ($3-4M). The Water Department has submitted an Action Plan to the DEP and has applied for State Revolving Funds.
Contact Time (CT Rule) The nearest house is only about 90 feet away from the Well. To meet the required CT for this site, the residual chlorine leaving the well must be high since the reaction time to the nearest house is short. This results in elevated chlorine residual levels in houses close to the well and complaints of smells of chlorine. For that reason, the DEP is encouraging the Town to install a contact tank or other means of providing longer reaction times before the water reaches nearby houses ($0.1-0.2M).
Septic Systems There are eleven houses and related septic systems within the Zone I (400 feet) of this well. There has been no documented contamination incident but the situation is not in compliance with the DEP regulations (this situation was grandfathered and would not be allowed under current regulations). The DEP wants the situation remedied ($0.4-0.5M).
Well #3 – Off Washington Street (Rte 16) in South Holliston
Due to its proximity to Rte 16, recreation fields, wetlands, and elevated iron levels in the groundwater, this well has not been operated for many years. The DEP no longer considers it a viable, active well so any future use will first require new source approval.
Well #4, and its associated water treatment plant, adjacent to Well #3 in South Holliston
Due to a continuing rise of the iron levels in the groundwater (from 1.5 mg/l in 1990 to 9.0 mg/l in 2009), neither this well or the related treatment plant have been run for over a year. Elevated levels of iron are an aesthetic issue, not a health issue; however, it can stain clothes and when oxidized, it turns the water yellow.
We do not know why the iron level in the groundwater are increasing. We have tried to remove it with a process using alum –alum attaches to the insoluble iron and the flock is then removed by settling. Regrettably, we soon found ourselves needing to use ten times as much alum as the iron we were removing; the clarifier clogged repeatedly requiring major downtime for backwashing and greatly reduced production time, so that process was discontinued.
Complicating matters, this well is situated on a narrow peninsula of land that is increasingly being encroached by the surrounding wetlands. Beavers are again an issue. Concerned about the influence of surface water, the DEP is now insisting on increased testing -- like that now required for Well #2 (MPA).
Note: this well is also down-stream from known contaminants that exist at the old Holliston dump and the now infamous Bird property, so continual monitoring of the groundwater for that reason is required.
The Water Department has been and is presently investigating two potential new well sites near Well #4. It is not yet known if these are viable. There is another site further away that is also being considered but if that is used it will require new source approval by DEP (years and money).
Cluster wells were also considered as a remedy, but further testing ruled them out due to similar water quality in the area.
If the existing water quality near Well 4 must be used, the existing Well #4 treatment plant will have to be reactivated and further modified. (Cost unknown)
Well #5 off Central Street
Two years ago this well was severely threatened by beavers and the backup of surface water which they created. The beavers were removed and their dams dismantled so the surface water could recede. This is now a good site.
Well #6 and its associated treatment plant off Brook Street
This is the newest of Holliston’s wells. Over the last year this well
experienced a rising level of manganese and a water color problem, neither being a health problem. Thus far, we have been able to remove the manganese (from above 2 mg/l to less than 0.05 mg/l) and the color (from 70 to less than 15 color units); however, the required coagulant and polymer additions have shortened the production time of the filters from 14 hours to 6 hours.
There is no obvious reason for the increased manganese and color; excess pumping is again suspect. However, there is also reason to suspect this could be the result of earlier blasting of the nearby ground rock and removal of up to 15 feet of filtering top soil and gravel to construct the nearby Fafard housing development.
Well #7 off Brook Street close to Well #6
This site was identified about 15 years ago and a test well was drilled at that time suggesting that this would be another a good water source. The fact that it is close to Well# 6 and could easily be connected to the existing treatment plant is another big plus.
Of course, given its proximity to Well# 6 there is now a question about whether or not Well#7 has also been impacted by adjacent activities, resulting in increased levels of manganese? At this time we are not permitted to further develop Well#7 or conduct another test.
The Well #7 site is on land controlled by the Army Corps of
Engineers. There is a long history of attempts by Holliston to get the
Corps to release this small track of land or, at least, give us access to the water. To date all attempts have met with nothing but bureaucratic resistance.
Summary
Holliston’s water supply remains available and potable. However, we are exceeding our DEP allotted pumping limit and, even more important, we are loosing our viable production capacity. Additionally, the Water Department is now facing a number of very expensive projects, some mandated by the DEP and some in search of ways to “simply” remove the iron, manganese and color from our water. Cost estimates are ranging from hundreds of thousands to multiple millions of dollars. A water rate increase later this year is unavoidable.
Good quality water is truly the life-blood of our Town. Hence, we want everyone to be aware of what is happening and to do whatever you can to conserve what we have.