LIKE THE OTHER two large suburban jurisdictions that sit astride the Capital Beltway, Prince George's County has a legitimate interest in preserving a swath of relatively rural land to safeguard the environment and a haven of green amid the region's helter-skelter sprawl. Yet unlike Fairfax and Montgomery counties, Prince George's has not really settled on a durable method of protecting the leafy environs on its southern and eastern flanks. That's what County Council members said prompted them to adopt a somewhat unorthodox new policy last fall, making the approval of new residential neighborhoods contingent on the provision of adequate fire, police and emergency medical service. At the time, officials predicted the policy would impede construction of no more than 100 houses, mostly in the county's rural tier, where fire and police stations are sparse. In fact, it has blocked at least 23 projects countywide, representing more than 1,300 homes, and left a dozen proposals for 1,000 more homes in limbo. In effect, Prince George's has imposed a moratorium on all new residential construction projects without quite meaning to do so.

This comedy of errors is instructive as a study in unintended consequences. Council member Douglas J.J. Peters (D-Bowie), who initiated the new policy, said he was assured by fire officials that they would be able to respond to emergencies at the proposed neighborhoods within the required five minutes. He was misinformed -- or failed to do his homework thoroughly in the first place. In fact none of the proposed neighborhoods met that standard for quick emergency service and therefore were stalled. Old construction projects already in the pipeline are being built, but new ones seeking approval have been frozen in their tracks.

Under pressure from the state and developers, the County Council is changing course. A new policy under consideration would relax emergency response standards to seven minutes instead of five and require developers of new residential neighborhoods to pay fees totaling about $15 million a year for emergency services. If a new neighborhood failed even the seven-minute emergency response test, the developer would be required to finance specific upgrades for local police or fire ser- vices -- a new squad car, for instance, or a fire engine. Some or most of those costs will be passed on to home buyers, further driving up soaring housing prices in Prince George's. That's fine with county officials, who think Prince George's already has more than its fair share of the region's affordable housing. But it will come as an unpleasant surprise to some home buyers, who might justifiably assume that basic services such as police and fire protection are the responsibility of all the county's taxpayers.

There are two problems here. One is that Prince George's residents themselves have hamstrung local government by imposing strict caps on property tax revenue, which are partly to blame for police and fire departments being perennially short-staffed and unable to keep abreast of population growth. The other is that the county has been slow to devise sensible, targeted means of limiting growth in rural areas, including clear rules for transferring development rights and promoting clustered houses in new neighborhoods to preserve open space and farmland. Until the county addresses these issues, it will be vulnerable to further clashes over development, rural areas and public safety.