David Pringle, campaign director for the New Jersey Environmental Federation, said a more accurate headline for the maps would be “Gov. Chris Christie reinstates 100,000 acres into development area.” He added: “This is an area we haven’t lost yet. It’s where we have endangered species’ habitats, wetlands and the source of much of our drinking water supply. Once you develop, you can’t go back.”

Efforts to address water quality management in New Jersey date back to 1996, when the federal Environmental Protection Agency ordered the state to update its sewer service network with an eye toward protecting endangered species and water supply. The state did eventually adopt new water quality management rules and ordered the counties to develop maps that would comply with those rules, but not until 2008. Court challenges by developers were among the factors that dragged the process out over a decade.

It was during that decade that 300,000 acres of environmentally sensitive land within areas designated as appropriate for sewer service were declared off limits (down from a previous 375,000 acres, after the Corzine administration removed parcels of 25 acres or less).

The current 209,000 acres deemed sensitive reflect more up-to-date data, according to Lawrence Hajna, a spokesman for the state Department of Environmental Protection. “The 300,000 acres was just a starting point — a ballpark number to begin the actual mapping process,” he said. “That then had to be ground-truthed for what’s actually happening, what’s been developed and what’s not.” He noted that since previous sewer maps had been published — the oldest of them dating to the mid-1980s — close to 18,000 acres had been added back into the sewer service areas statewide.

The counties’ new sewer maps, which are expected to receive final approval by the end of the year, represent the first in a three-step process to address water management issues. In legislation passed in December, counties were given two additional years to complete the two remaining steps: an analysis of how sewer plants already in place could accommodate the waste generated if everything deemed buildable under current zoning went ahead; and a plan for policing sections outside sewer areas, which use septic systems.