For now, and at least through the next century, water supplied by the Triadelphia and Rocky Gorge reservoirs on the southern border of Howard County is expected to be clean and drinkable.
But the threat of sprawl from Baltimore and Washington could eventually convert them into algae-filled wetlands with water unsuitable for human consumption.
That is the concern of an official from the Washington Suburban Sanitary Commission (WSSC), a state-authorized utility run by commissioners appointed by Prince George's and Montgomery county executives that has owned and operated the Triadelphia and Rocky Gorge reservoirs since they were built in the 1940s.
"I think we are at a crossroads because of development pressures in Howard County and Montgomery County," said William J. Kennedy, environmental affairs manager for the utility's bureau of planning and design. "They're beautiful areas and prime for development. We feel the stressors on the lakes at a point where we don't want [development] to go any further. We're trying to hold the line."
Kennedy's comments came nearly two months after the state's top environmental official criticized Howard County officials for allowing dense residential development near the reservoirs.
Jane T. Nishida, secretary of the Maryland Department of the Environment, subsequently stripped the county health officer, who works under Nishida's jurisdiction, of the authority to approve subdivision plans using private septic systems and wells. Her office is also conducting an audit to review the local health department's endorsement of about a dozen residential communities in the western section of the county.
The audit, to be completed by the end of the month, likely will show whether local health officials ignored state environmental guidelines and whether Nishida can rescind the county health officer's authority for an indeterminate amount of time.
State regulations require communities developed within 2,500 feet of watersheds to build a house on a minimum lot size of 2 acres.
The county allows developers to build a home on no more than 1.5 acres near reservoirs. A county councilman has introduced an amendment that would match the county code with state standards.
Two communities -- both offering a house per acre -- have been built within 2,500 feet of the Triadelphia and Rocky Gorge reservoirs. Kennedy said it is unlikely that the developments have had much negative impact on them.
But Kennedy said the demand for new housing in previously undisturbed areas is becoming a national threat to drinking water sources.
"We're pushing the envelope," he said. The Triadelphia and Rocky Gorge reservoirs make up part of the border between Howard and Montgomery counties. The Patuxent River flows through both reservoirs.
About 70 percent of the water from the reservoirs serves residents in the northern half of Prince George's County. Another 25 percent flows to northeastern Montgomery County, while 5 percent is consumed by residents of southern Howard County.
The WSSC, which also manages water from the Potomac River, has been monitoring water quality in the Triadelphia and Rocky Gorge reservoirs every month for more than 20 years.
Although Kennedy said water quality from the reservoirs is "10 times better" than water from the Potomac River, he noted that contaminants in the reservoirs' water are on the rise.
Oxygen levels in the lower layers of the water are less than the 5 milligrams per liter required to sustain the aquatic life that feeds on algae, which can give water a foul odor and taste.
Pub Date: 7/04/99