By Dan Aceto

Staff Writer

Proposed regulations for the containment of hazardous chemicals and waste on land above the town’s aquifers could better protect public drinking water in north Scarborough. 

The north Scarborough area accounts for nearly half of the land in town, said Town Planner Dan Bacon. It is located at the intersection of County Road, Saco Street, Beech Ridge Road and Gorham Road. 

An aquifer is a naturally occurring underground stream of water that is a vital source of drinking water, he said.

Bacon said sand and gravel aquiferssuch as those in Scarborough are particularly vulnerable because contaminants can easily travel through their porous surfaces.

The proposed Aquifer Protection Overlay District would establish new standards for wastewater systems, fuel tanks and lines, chemical and petroleum storage, floor drains, storm water management, groundwater withdrawal and application of manure and fertilizers on land above the town’s 10 sand and gravel aquifers.

The zoning board would determine the district by using information provided by the Maine Geological Survey on the size of each aquifer. The town’s code enforcement department would ensure guidelines are met in the overlay district.  

The Town Council was expected to address the issue Wednesday, after the Leader deadline. The Planning Board is scheduled to review the proposal March 7.

Bacon said the impetus for the proposal is prevention. 

“Generally we’re trying to prevent leakage and spillage from petroleum and chemicals into the sandy soil,” Bacon said.

The new regulations would prohibit disposal of  solid wastes, leachable wastes and sludge and storage of wastes in an amount no greater than what is typically associated with the use of a site.

The storage of gasoline and petroleum in excess of 100 gallons for homeowners would be prohibited except for storage of fuels for use on-site. 

Non-residential businesses would be limited to storage of 275 gallons, and would have to meet safety standards.

Wastewater systems with a capacity of 1,250 gallons would be required to demonstrate that nitrate levels do not exceed 5 millileters per day. 

Bacon said that high nitrate levels could cause water quality issues due to bacterial growth.

The regulations would give new or replacement tanks used to store heating oil must have double walls and new or existing unprotected fuel lines be replaced with a line equipped with a special sleeve to prevent leaking.

Floor drains would not be permitted in any building, residential or non-residential, where chemical and petroleum products are used. This excludes foundation drains, discharges of groundwater or storm water from sump pumps or similar uncontaminated discharges of groundwater or storm water.

Bacon said the town’s decision to form the Aquifer Protection Overlay District was first discussed in 2009 when the Comprehensive Plan Implementation Committee (CPIC) met with residents to discuss two proposed zoning changes in north Scarborough. 

He said residents at neighborhood meetings were concerned about how close the town’s ground water supply was to the land surface.

Residents also were concerned about potential impact hazardous chemicals and waste could have on drinking water for the town’s largest aquifer in north Scarborough that encompasses the Stroudwater River, Red Brook and Nonesuch River watersheds.

He said the town’s Comprehensive Plan, which was updated in 2006, also indicated the need to provide additional protection for sand and gravel aquifers in the area, particularly for those that are a source for drinking water.

He said residents and businesses in north Scarborough rely upon on-site wells and wastewater management systems forw water and sewage.

“It’s an area not served by public utilities,” Bacon said. “The sewer service is more vulnerable given that the wastewater septic system working in those areas has the potential of impacting the aquifer, and frankly, everyone there is dependent on the aquifer for drinking water.” 

Other areas of town rely on drinking water from public utilities.

Councilor Mike Wood, who serves as a liaison for the Comprehensive Plan Implementation Committee, said the aquifer located in north Scarborough produces the highest yield in town and generates more than 50 gallons of water a minute.

“It’s amazing the size of them and the potential negative impact that would take place if a significant spill were to occur for the many that rely upon the aquifer for drinking water and irrigation,” Wood said.

Town Manager Tom Hall agreed. 

“This recognizes the tremendous value of the aquifer in Scarborough,” Hall said.

Wood said the Aquifer Protection Overlay District would provide an easy and convenient way for residents and business owners to identify where overlay districts are and allow them to deal directly with the planning department for information on restrictions.

Staff Writer Dan Aceto can be reached at 282-4337, ext. 237.