 |
||||||||||
|
||||||||||
|
|
||||||||||
|
Land Use Department Plan of Development 7.0 WATERSHED AND AQUIFER PROTECTION In Bethel, four major stratified drift aquifers and surface water reservoirs are used for public water supply. Because the Dibbles Brook, East Swamp, Limekiln Brook, and Sympaug Brook aquifers are an essential natural resource and a major source of public drinking water in Bethel, their protection is paramount. Furthermore, use of groundwater is likely to increase, as the population grows and opportunities for new surface water supplies diminish due to the rising cost of land and increasingly intense development. This memo will focus on protection measures for Bethel's water sources, and act as a guide so the town can implement its own Watershed and Aquifer Protection Program. Bethel needs to take steps to protect its stratified drift and bedrock aquifers. Groundwater (aquifer) contamination occurs through inappropriate zoning, chemical discharges, failing septic fields, and other land use development results. According to the Housatonic Valley Council of Elected Officials' report Regional Water Resources and Supplies (Dec. 1993), "[c]ommon groundwater contaminants in Connecticut are pesticides, nitrates, solvents, gas and oil, and road salt. The state has mandated that municipalities protect their aquifers in order to preserve the quality of potable water. State DEP (Department of Environmental Protection) has requested that Bethel undertake a procedure call Mapping A, to control salt storage on ground over the aquifer. This first stage is voluntary, but it is expected that the DEP will eventually require that zoning regulations be enacted to protect the aquifers. Bethel could possibly adopt the DEP regulations as its own in order to be in compliance. At present, Bethel's source protection program has several non-regulatory and regulatory aspects, with no local program specifically for groundwater protection. In place are wetland and watercourse regulations, state regulations on pesticide and fertilizer use, and the donation of open space created by residential development to the Bethel Land Trust. Additional protective measures could include a stratified drift aquifer overlay zone, a residential fuel tank control ordinance, and a hazardous materials management ordinance. The town should also investigate its salt storage facilities and salt-spreading measures.
Public Water Supply Watershed Bethel is served by Eureka and Mountain Pond reservoirs, both of which are located in Danbury. The Eureka system is supplemented by the Chestnut Ridge Reservoir, located in southern Bethel, and the Maple Avenue wells, located north of the central business district area in the East Swamp Aquifer. There are two local utilities. The private Consolidated Water Co. serves the Chimney Heights/Stony Hill area. The municipally-owned Bethel Water Department currently serves the downtown and central core, approximately 7,778 people or 46% of the population. Bethel owns 42% of the Eureka Reservoir Watershed, 46% of the Chestnut Ridge Reservoir Watershed and 100% of the Maple Avenue wellhead radius. There are 635 acres dedicated to water department use. The Chestnut Ridge system serves a predominantly residential area with a small amount of commercial use along Greenwood Avenue. The Eureka system serves all industrial zones, as well as most of the commercial zones. According to the 1995 Water Supply Plan, the safe yields for Chestnut Ridge Reservoir are 0.17 million gallons per day (MGD), Eureka Reservoir- 0.20 MGD and Mountain Pond - 0.13 MGD. The combined safe yields for the Maple Avenue Wells are 1.16 MGD. The maximum amount of water that the Bethel Water Department can dependably supply equals the sum of the safe yields of all sources during the critical dry period, or 1.66 MGD. The amount of available water in excess of demand is expected to permit projected population increases and anticipated system expansion without adversely affecting the existing quality of service. Aquifers The aquifers in Bethel are gravel areas beneath the soil that are capable of storing large quantities of water. They are technically known as "stratified drift aquifers" as they were originally deposited by glacial meltwaters. These aquifers contrast sharply with the remainder of the town, where bedrock is tapped for water supply. The difference in yield between two areas can be dramatic; perhaps a million gallons per day for a well in the aquifer, but only a few thousand gallons per day or less for a bedrock well. Generally speaking, large wells for public purposes are only drilled into the stratified aquifer and not into bedrock. Both types of groundwater sources are of course entitled to land use regulatory protection. However, the contamination of just one public well on an aquifer, serving thousands of homes, is so catastrophic that aquifer protection has had its own regulatory history, aside from the parallel protection of bedrock areas through health code standards and other techniques. A significant contributing factor to separate regulation is that aquifers are almost always in low flat areas, traditionally the locations of business and industrial zones, where risks of contamination are highest. Bethel Water Department has been exploring possible new well sites. One site has already been selected for future wells and two more are under consideration. Test wells have been drilled on the 64 acre site behind the Police Station in the East Swamp Aquifer. Test wells are also being drilled on Kristy Drive, located in the Dibble Brook Aquifer, off Old Hawleyville Road, north of Route 302. The Grassy Plain Wells, tapping the Sympaug Brook Aquifer, have been out of use since 1964 due to chemical contamination. The Parloa Well Field, also in the Sympaug Brook Aquifer, is no longer used due to the construction of sewers nearby, raising the risk of contamination, although these wells are not now contaminated. 7.3 State of Connecticut Department of Environmental Protection Mandates Public Water Supply Watershed Public Act 85-279 entitled "An Act Concerning the Protection of Public Water Supplies" requires, rather than allows, municipal Planning and Zoning commissions to consider protection of existing and potential public surface water supplies in their plans and regulations. Bethel's 1996 Water Supply Plan discusses actions taken by the Bethel Water Department in response to a "check list of municipal actions to consider," issued by the Connecticut Department of Environmental Protection. These measures are discussed in 7.4. According to the Connecticut State Legislature, use of groundwater is likely to increase, as the population grows and opportunities for new surface water supplies diminish due to the rising cost of land and increasingly intense development. The legislature has, therefore, determined that protection of existing and future groundwater supplies demands greater action by state and local government. Aquifers The state's Aquifer Protection Program intends to advance groundwater protection by:
In 1993, the Connecticut State Legislature promulgated an "Act Concerning Aquifer Protection Areas." This act is designed to "ensure a plentiful supply of public drinking water for present and future generations" by preventing contamination of ground water in areas around public wells. The act requires the Department of Environmental Protection to adopt comprehensive land use regulations, which include prohibitions, mandatory best management practices, and procedures for local program management. The act also requires municipalities to conduct land use inventory, designate an existing board as the aquifer protection agency, register existing regulated activities, prohibit or permit new regulated activities, inspect regulated activities, and adopt local regulations. The Connecticut Department of Environmental Protection requires all towns with utilities serving more than 1,000 people to:
Bethel has completed Level B maps of the areas of contribution and recharge areas. Connecticut Department of Environmental Protection is in the process of creating a Model Municipal Ordinance to assist towns in adopting required land use regulations. There are other small stratified drift gravel deposits in Bethel, including along parts of Route 58. However, the statewide Connecticut Department of Environmental Protection led regional delineations of aquifer management areas did not include such smaller areas, as they were of insufficient depth or had overall limited transmissivity to be considered viable as public water supply system well sites. This does not mean that groundwater quality protection there should be ignored; small bedrock wells will be drilled through the aquifer in those locations and thus such areas are in need of long term protection. The approach of the 1980 and current groundwater protection program of Connecticut Department of Environmental Protection, Housatonic Valley Council of Elected Officials, and the United States Geological Survey is to only regulate what really needs to be regulated; minimize the boundaries as much as possible. That is why the setting of aquifer boundaries in effect "chopped off" some aquifer areas of lesser value, such as along Route 58. It was felt that new restrictions on property use to preserve groundwater should be required only for aquifers that were known to be large enough to be of use to a public supply system. 7.4 Bethel's Current Protection Measures for Water Supply Watersheds and Major Aquifers Bethel Water Department conducts annual watershed inspections in the watersheds of both the Eureka and Chestnut reservoirs. There are a few homes and commercial and industrial sites in the watersheds. Since town development plans presently restrict construction of homes within the service area (500 new units limitation), and limit industrial development to those areas presently zoned for such activity, the potential for contamination is reduced. Until recently, the only real potential sources of pollution have been non-point sources: a livery stable, fuel delivery vehicles, road salt, subsurface sewage, subsurface fuel tanks and pavement runoff that might carry automobile antifreeze, washing compounds or oil into the reservoirs. Chemical lawn service trucks are a new hazard which will require strict controls. Bethel has adopted all DEP regulations pertaining to groundwater protection, and has required utilities to purchase or obtain controlling interest in the land within a 200 foot minimum radius of most public water supply wells. Bethel does not have, however, a local source protection program of its own. Measures Bethel has taken to protect its surface and groundwater are as follows: Non-Regulatory Measures
Regulatory Measures
7.5 Recommendations for Bethel for Public Water Supply Watersheds and Major Aquifers Bethel should create a local aquifer and watershed program, delineating all local aquifers and watersheds, and carefully describing the hazards to be avoided in and around its wellfields. The following recommendations will help to initiate this program. (See Figure 15, Aquifer and Watershed Protection: Proposed Regulatory Measures.) Regulatory Measures Zoning
Subdivision Regulations Because the Bethel Water Department owns most of the land surrounding its watersheds, development is limited and contamination is, thus, reduced. However, Bethel has not specifically addressed the protection of land surrounding its groundwater recharge areas. Furthermore, Bethel's conservation subdivision program falls short of providing effective regulatory measures for the protection of public drinking water supplies. For developments in recharge areas, the Planning and Zoning Commission should require a comprehensive environmental analysis to determine the following:
Inland Wetlands and Watercourses Bethel's Inland Wetlands and Watercourses Commission has the authority to restrict development in sensitive watershed areas (see Figure 16) to prevent degradation of water supplies. However, this authority is inadequately supported by the existing regulations because the regulations do not specify stream and wetland setback requirements. The following conditions should become part of the inland wetlands and watercourses regulatory program:
It should be noted that Figure 16 is not the official wetlands map and cannot be used for official or legal purposes. It is a general reference map produced for the Plan of Development solely to help the reader understand existing conditions in the town. Applicants before the Inland Wetlands and Watercourses Commission must have their property separately mapped by a wetlands expert and flagged in the field. Figure 16 does not replace specific on-site wetlands investigation. Figure 16: Wetlands and Streams Residential Fuel Tank Control Ordinance Although there are no federal or state regulations pertaining to residential underground storage tanks, many Connecticut municipalities have already acted on their own to protect their groundwater. Several measures Bethel can take to do the same are:
Hazardous Waste Materials The purpose of a hazardous waste materials ordinance is to regulate commercial and industrial use and storage of hazardous substances and chemicals. This ordinance would be directed at all existing and future users of hazardous materials.
Open Space Bethel requires a percentage of land in new conservation developments to be preserved as open space, in R-40 and R-80 Zones. The percentage to be deducted, however, in no way correlate open space requirements with water quality protection in sensitive recharge areas. Conservation subdivisions should also be encouraged in areas surrounding the recharge area. Non-Regulatory Measures Household Hazardous Materials Public awareness of the effects that fertilizers and pesticides can have on drinking water needs to be buttressed. Bethel should increase its collection of hazardous materials to at least once a year, if not more, to raise awareness and reduce impact of improper disposal on drinking water. State funding is available to municipalities for a program of this type. De-icing Salts The use of calcium chloride/sand mix should be considered. This mixture is just as corrosive as sodium chloride alone, and can actually reduce the sodium levels in water supply. It is also less toxic to vegetation than sodium chloride alone. Bethel would need additional storage facilities and equipment capable of spreading this material. A calibrated spreader would allow more effective control over the rate of sand to salt application in watershed and recharge areas. The primary sand/salt mixture per eight mile run should be mixed at a ratio of eight parts of sand and one part of salt on roadways in the public drinking water supply. A de-icing salt management policy and procedure incorporating the above recommendations should be developed by the Public Works Department to provide an acceptable standard of winter maintenance. 7.6 Aquifer and Watershed Protection Programs Around the Region Brookfield Brookfield has an "AP District" which is an aquifer overlay zone, in the zoning regulations. Its zoning regulation contains specific wastewater effluent standards and wastewater loading rates by soil type and slope. Danbury Danbury's hazardous materials management ordinance, adopted in 1982, has served as a model for other communities in Connecticut. Furthermore, Danbury implemented a comprehensive water supply watershed protection strategy in August of 1993. Within the former are residential fuel tank control features for new developments in watershed areas. These include underground tank installation requirements such as requiring the tank to be placed in a vault, liner or double lined containment system; requiring a leak detection system, and requiring overfill protection. Above ground tank installation requirements include a roofed secondary containment area with a cleanout sump or a "tank within a tank" secondary containment alternative design. Furthermore, the owner of any underground storage tank in a Class I or Class II watershed area must register the tank and tank system with the Danbury Health Department. "The Public Water Supply Watershed Protection Zone" is an overlay zone regulating activities on Class I and Class II watershed areas. The watershed boundaries have been mapped. The regulations governing activities within these boundaries 1) prohibit certain uses, 2) require certain performance standards, and 3) require environmental impact analysis before development. According to Danbury's Planning and Zoning Department, this protection zone has been useful in allowing development to proceed in a careful way, without impact to environmentally sensitive land and without requiring the extension of public sewer service. Newtown There is an aquifer overlay zone, adopted in 1981 for the Pootatuck Aquifer. In 1994, a Residential Fuel Tank control Ordinance was proposed which would regulate and prohibit the following: (1) new installations or replacement of underground tanks are prohibited in areas of high groundwater or wetlands as defined by soil tests, and the aquifer protection zones; (2) a permit must be obtained to install storage tanks or bury transmission lines; (3) a safety shield or sleeve is required if transmission lines are buried in soil or through concrete; and (4) underground installation of either new or replacement storage tanks is prohibited, unless special exception is obtained. There are no, as of yet, formal watershed protection regulations in Newtown. Redding A draft aquifer protection overlay zone was prepared in 1990. This regulation would include residential fuel tank control regulations. |
||||||||||
