Dear Members of the Board of Selectmen and the Board of Finance,
I would like to clarify some issues concerning the likely effects of development on the Stratton Brook aquifer if the Ethel Walker development rights are not purchased by the town.
This aquifer is a particularly shallow one, the water table being mostly within 30 feet of the surface [1], and is therefore particularly susceptible to contamination.  The only way to ensure that this aquifer will continue to provide pure drinking water is to make sure that the land above it remains undeveloped.
The DEP, in its Bulletin No. 26 (Protecting Connecticut’s Groundwater, A Guide for Local Officials), shows five categories of risk to groundwater, ranging from 1 (lowest risk) to 5 (highest risk). Category 1 includes nature preserves and open space (passive recreation only): this is what we have now. Category 2 includes residential (2-acre lots); Category 3 includes residential (1/2- to 1-acre lots). According to the figures presented in the preliminary development plan for the Walker Woods, which is the only plan that has been made public, the average lot size in this development would be 1.4 acres, somewhere between Category 2 and Category 3. The risk for this particular development, even on a deeper aquifer, would therefore be better characterized not as “low”, but rather as “moderate”. And this aquifer is a shallow one, which increases the risk level.
For example, one of the most serious risks is the use of pesticides. Pesticide use has doubled since Rachel Carson’s Silent Spring was published in 1962. The USGS National Water Quality Assessment Program in 2002 found that low concentrations of pesticides are in streams and groundwater throughout the nation. At least one pesticide was detected in more than 95% of stream samples collected at 115 sites. Furthermore, nearly two thirds of all streams sampled had at least one pesticide at a concentration exceeding a guideline for the protection of aquatic life. In studies of major rivers and streams, 96% of all fish contained one or more pesticides at detectable levels.
Pesticides, along with the so-called “inert  ingredients” that usually make up most of a pesticide formulation, are by no means harmless. Many of these chemicals can have serious health risks even at concentrations in the low parts-per-billion or parts-per-trillion range. The “inert ingredients” may in some cases be more toxic than the active ingredients.  Again, from the DEP Bulletin: “With few exceptions, little is known about the long-term health effects that may result from consuming these substances at low levels in drinking water. Only a few of the more than 50,000 chemicals currently in commercial production have ever been studied to evaluate their long-term health effects … In private wells, which are seldom tested, contaminants may go undetected for a long time…  Even minute amounts of [toxic synthetic organic] chemicals in groundwater can threaten human health. What’s worse, these chemicals are often persistent in soil and water and may affect groundwater for many years.”
A lot of these toxins are coming from residential lawns. The U S Fish and Wildlife Service found that homeowners use up to ten times more chemical pesticides per acre on their lawns than farmers use on crops. It has been estimated that 500,000 to 1,200,000 pounds per year of pesticide active ingredient are applied in residential areas of Connecticut (1990: DEP Bulletin No. 11).
Most lawn care chemicals have the potential to contaminate groundwater. The four top-selling lawn care pesticides, 2,4-D, glyphosate,  MCPP, and dicamba (all of which are abundantly available in stores in Simsbury and Avon), are listed by the State of California as being potential groundwater contaminants based on their physical and chemical characteristics such as water solubility and half-lives in soil and water. Some lawn care chemicals can persist in soil and water for years. Once water becomes contaminated, studies to determine the source of the contamination problem are costly, time consuming, and sometimes inconclusive. Remedial action, if it is even possible, may take ten to twenty years and is likely to be very costly and disruptive. “The effectiveness of such [remediation] systems – which require regular maintenance – varies widely. Some contaminants, like nitrates [from fertilizers] and salt [from roads], can only be removed by expensive reverse osmosis units. Removing these contaminants in large amounts of water is not generally feasible.” (DEP Bulletin No. 26) Full restoration of groundwater quality is seldom if ever achieved.
According to the same DEP Bulletin, additional “residential higher-risk activities include: certain home occupations…[such as] lawn care businesses; photo processors;…printers; furniture strippers and finishers; reupholsterers; electrical, radio, and television repair; appliance, lawnmower, and small engine repair; heating and cooling equipment service; pesticide applicators and exterminators; etc.”  Lest one think that people in million-dollar homes would be unlikely to be engaged in such businesses, it is important to remember that once the subdivision permits are granted, there is no guarantee that the houses built there will be million-dollar ones, regardless of what is presented in the plans. Changing market conditions could cause the developers to rethink the plans without having to obtain new permits.
Other groundwater risks from residential activities, again as listed in the  same DEP Bulletin, include: “Fertilizer – use, storage, disposal; Fuel oil storage; Household hazardous materials – use, storage, disposal; Pesticides – use, storage, disposal; Septic tank additives; Septic systems – improper siting, design, installation, use, maintenance; Stormwater runoff; Waste oil and antifreeze disposal; Water conditioner – discharges; Water conservation – lack of it.”
According to the DEP, “Natural open space … represents the lowest level of risk to groundwater. Such open space, especially if managed by or in cooperation with a water utility, provides one of the most effective approaches for protecting critical groundwater resources.” (Bulletin No. 26)
For these reasons alone (although there are many others as well), the preservation of the Ethel walker Woods in its natural state should be of the highest priority to Simsbury town officials. I urge you to do everything possible to support the town’s purchase of the development rights to this property, starting with sending this issue to referendum.
Dr Susan B. Brachwitz

[1] “Availability of Water from Stratified-Drift Aquifers in the Farmington River Valley, Simsbury, CT.”, by R. L. Melvin and J. W. Bingham, USGS, 1991.