Date: Fri 12-Jul-1996

Publication: Bee

Author: ANDYG

Quick Words:

Apple-Blossom-contamination

Full Text:

Consultants Recommend Public Water For Area With Contaminated Wells

B Y A NDREW G OROSKO

In a draft report, an environmental consulting firm is recommending that

United Water's public water supply system be extended to serve residents of

Apple Blossom Lane, Dogwood Terrace and portions of Cedar Hill Road whose

domestic water wells have been tainted by the industrial solvent

tetracholoroethylene (PCE).

SEA Consultants, Inc, of Rocky Hill estimates that the cost to extend water

mains to affected properties would be approximately $1.74 million.

The recommendation is contained in a June 1996 SEA draft report that analyzes

water pollution data collected by the consultant, the town, and the state

Department of Environmental Protection (DEP).

Town Health Director Mark Cooper said the town plans to conduct a public

informational meeting with affected residents soon to inform them of SEA's

findings.

"Please keep in mind this is a draft report that is undergoing review by the

appropriate town and state agencies. I expect there will be some discussion

and possible revision to the draft before it is finalized, submitted to the

DEP and presented to the Apple Blossom area residents," according to Mr

Cooper.

The public informational session will be conducted as soon as possible, he

said.

In its draft report, SEA confirms that groundwater in the Apple Blossom Lane,

Dogwood Terrace and Cedar Hill Road area is tainted by PCE, which originated

from an unidentified source or sources in the area.

PCE also is known as percholoroethylene, perc, perclene, perchlor and

tetracholoroethene. The chemical is used as an industrial degreasing compound

and as a solvent in the dry cleaning of fabrics.

According to a toxicology draft report prepared the US Department of Health

and Human Services (DHHS), the health effects of drinking water with low

levels of PCE are not known. Results of animal studies, conducted with amounts

of PCE much higher than most people are exposed to, show that PCE can cause

liver and kidney damage and cause liver and kidney cancers. The DHHS has

determined that PCE may reasonably be anticpiated to be a carcinogen or

cancer-causing agent.

Apple Blossom Area

Apple Blossom Lane area residents affected by the PCE contamination get their

water supplies from bedrock wells on their properties. The underground

movement of that groundwater is extremely difficult to determine due to an

extensive network of interconnected fractures in the subsurface ledge,

according to SEA.

Area groundwater appears to flow in a northerly direction, possibly turning

toward the northeast between Dogwood Terrace and South Main Street.

It is suspected there have been multiple sources of PCE contamination in light

of the high levels of PCE in groundwater in the neighborhood and near South

Main Street, according to SEA.

Because no specific source of PCE contamination has been established, the

state has assumed jurisdiction in the case, plus the ultimate financial

responsibility for rectifying the pollution problems.

The substance known as MTBE, which is a chemical additive to gasoline, has

been observed in several water samples taken in the area. Its presence doesn't

pose a health risk in the concentrations which have been observed, according

to SEA. MTBE is mixed with gasoline to reduce carbon monoxide pollution.

The PCE contamination in the neighborhood apparently is limited to a bedrock

valley there and a thick overburden of soil lying above the valley, as well as

an area near a meandering stream, according to the consultants.

The groundwater contamination which has been observed in the area of Dogwood

Terrace, Apple Blossom Lane and Cedar Hill Road doesn't now appear to be

traveling or migrating, according to SEA.

It is unknown how subsurface water in the area would be affected by the

installation of water mains, when considering that groundwater there no longer

would be drawn down by domestic water wells, according to SEA.

Currently, contamination appears to be limited to the area bounded to the

north by Dogwood Terrace and to the southeast and southwest by 22 Cedar Hill

Road and 40 Cedar Hill Road, respectively, according to SEA. The highest

levels of contamination have been located at 32 Cedar Hill Road, 50 Apple

Blossom Lane, 3 Dogwood Terrace, and 4 Dogwood Terrace. Water contamination

levels decrease away from these properties, according to SEA.

The pollutants appear to have sunk into the ground from the surface and then

hit a bedrock aquifer.

Water testing has detected the presence of PCE in 41 wells, of which 14 wells

have relatively high levels or "action levels" of the substance.

All 41 wells have at least 0.5 parts per billion of PCE in their water which

is considered the "trace amount" of PCE.

Fourteen of those wells have water which exceeds 5.0 parts per billion of PCE.

Activated charcoal water filters have been installed at residences where well

water has high PCE levels. Residents with wells with lower PCE levels use

bottled water for drinking and cooking.

Possible Solutions

If all affected homes were to receive water filters, homes along the perimeter

of the affected area would require regular water quality testing to measure

whether the pollutants are migrating, according to the consultants.

SEA estimates that installing water filters and monitoring them across a

20-year period would cost approximately $1.52 million.

Another permanent solution would be connecting the affected homes to the

United Water public water supply system, according to SEA.

A third alternative would involve combining an extension of the water supply

system with the installation of some water filters.

In its recommended solution, SEA calls for the extension of the United Water

public water supply system, as well as the installation of three water

filtration systems for individual residences at 64 Cedar Hill Road, 11 Megans

Circle and 1 Old Gate Lane.

In conducting its study of the groundwater pollution problem, SEA mailed

questionnaires to more than 150 homeowners in the area who are affected by

well water contamination or potentially may be affected by it. The responses

indicated that the only acceptable solution would be the extension of water

mains on Apple Blossom Lane, Dogwood Terrace and portions of Cedar Hill Road,

according to SEA.

Even if water mains were to be installed, water quality testing would be

continued at the perimeter of the area for 20 years to learn if the

contaminants are moving.

In its draft report, SEA provides three alternative water main layouts.

The basic version of the plan, Option A, provides basic water supply service

to affected properties at a cost of $1.74 million.

Option B provides a pipe layout with "looped ends" that would make for better

water supply reliability and better water quality. That layout would be more

extensive and more expensive than Option A at a cost of $2.29 million.

A yet more elaborate Option C would provide water service to all homes that

are passed by water mains at a cost of $2.4 million.