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Sussex County officials have once again fine-tuned an ordinance designed to protect public drinking water.
After rewriting the original source-water protection ordinance, as proposed by a citizens’ advisory committee, the council made additional changes Tuesday, Feb. 26, and introduced a new ordinance for consideration.
After reviewing the rewrite, the citizens’ advisory committee made five additional recommendations. But unless you are a hydrologist, you will have trouble understanding the changes or the ordinance.
However, the foundation is about protection of drinking water, said Delaware Department of Natural Resources and Environmental Control (DNREC) senior hydrologist Doug Rambo. The ordinance outlines wellhead protection areas and excellent recharge areas and regulations within those areas.
“Groundwater is Sussex County’s sole source of drinking water in public and domestic wells,” he said. “The protection of groundwater through the use of overlay zoning [wellhead protection and excellent recharge areas] is going to help by minimizing threats that could impact the quantity and quality of groundwater.”
The new ordinance contains stricter regulations than recommended by the citizens’ committee, including the same impervious surface regulations for excellent recharge and wellhead protection areas. Any project with more than 35 percent impervious surface will need to provide an environmental survey outlining mitigation plans to deal with water runoff.
A public hearing must be scheduled before county council can vote on the ordinance, which was supposed to be in place Dec. 31, 2007, by state mandate. The adoption of a source-water protection ordinance is key to state certification of the county’s updated comprehensive land-use plan.
Time of travel
Time of travel of water within the wellhead protection areas became an issue in the final discussion before council could proceed to introduce the ordinance.
The citizens’ committee wanted a less-stringent 60-day time of travel as the requirement to designate smaller wellhead protection areas. DNREC officials wanted much larger areas designated by a five-year time of travel.
Time of travel is the approximate time that elapses when a drop of water infiltrates the land surface until it enters an aquifer or reaches a specific target such as a spring.
Rambo said the five-year time frame is the amount of time it would take a drop of water or containment from the edge of a wellhead protection area to show up in a well.
Contaminants spilled within the wellhead protection area would reach the well faster.
“The five years allows water suppliers time for contingency planning,” Rambo said. That would allow time for addition of a new well or water treatment.
He said the perfect example to illustrate time of travel and how long it takes pollution to be discovered is the trichloroethylene contamination that appeared in Dagsboro and Millsboro wells in 2005 and 2006. He said the contamination came from a facility, a former poultry vaccine manufacturing plant, at the edge of the town’s wellhead protection area.
“It was almost five years to the day when the facility was abandoned and the contamination started to show up,” he said.
The plant was in operation from 1952 to 1999 and demolished in 2000.
New ordinance
The council reached a compromise when it adopted both time-of-travel designations in its ordinance.
Wells pumping 50,000 gallons or more per day in confined aquifers would have wellhead protection areas delineated with groundwater flow models showing a 60-day time of travel.
Wells pumping 50,000 gallons or more in unconfined aquifers would have wellhead protection areas delineated with groundwater flow models showing a five-year time of travel.
Safe zones in these areas would have a 100-feet radius (200 feet across) from a well. No construction, other than well facilities and piping, would be permitted in safe zones.
Wells pumping less than 50,000 gallons per day in confined or unconfined aquifers would not have time-of-travel restrictions to determine the wellhead protection areas. The safe zones would be in a 20-foot radius from the well.
Unconfined aquifers, where most wells in the county are located, are shallow aquifers also called water-table aquifers. They usually receive water directly from the surface, from precipitation or from bodies of water. They are most susceptible to pollution.
Confined aquifers are much deeper, located beneath unconfined aquifers.
County Administrator David Baker said DNREC officials approved of the changes.
Rambo said a time-of-travel limit is not as critical in the confined aquifers as it is in the unconfined aquifers. “The confined aquifer has protection built it because the confined unit is normally clay or silt,” he said. “It might take a containment months to years to decades to get through the confinement.”
Baker said the ordinance applies to major subdivisions, wells with public water supply, and conditional-use and rezoning applications. He stressed that the ordinance would not apply to individual residential lots.
Exemptions from the ordinance include the following: private residential wells; agricultural wells; replacement wells; minor subdivisions; designated well areas in existing recorded subdivisions; improvements to existing residential lots.
Rambo said the new county ordinance is an improvement over the original. “The new version has come a long way. The county has done a good job,” he said.
Not all members of the citizens’ advisory committee agree. “Why is this back on the agenda?” asked member Dan Kramer. “Because of DNREC,” he said.
“You should have passed the old ordinance,” he told council members.
Contact Ron MacArthur at ronm@capegazette.com
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