A compromise coastal stormwater rules bill passed unanimously through the state Senate environmental committee Tuesday, its first test toward passage by the General Assembly.

The more stringent rules, which are designed to protect shellfishing waters in 20 coastal counties, have been in development for three years. The proposed rules, which will affect both Pamlico and Craven counties, have undergone changes to create compromise in recent months by state regulators and stakeholders.

The compromise bill passed the 20-member Senate environmental committee, which includes Carteret County Sen. Jean Preston.

The bill next goes to the full Senate. If passed, the House environmental committee that includes vice chairman Rep. Alice Underhill of New Bern could vote on it Tuesday.

Pamlico County Commissioner Chris Mele, who earlier said the original rules would be devastating to the county's growth, told her board Monday night that the compromise rules were palatable.

Tom Reeder, deputy director of the state Division of Water Resources, was the main author of the rules.

"We feel that the compromises will make the rules implemental for the regulated community and still will be protective of coastal water quality, which is what we wanted all along," Reeder said Tuesday.

Some of the main compromises involved wetlands, language on disturbed land surface, buffer restrictions and grandfathering of existing plated lots.

Exemptions from the buffer requirements should ease Pamlico County concerns on grandfathering existing lots, almost all of which Reeder said would be exempted.

 "Anybody out there that has an unbuilt residential plated lot, there is very little chance these rules will affect you," Reeder said.

Another compromise is in determining how much of a lot can be built upon and the size of projects requiring a stormwater permit. Whereas no wetlands could be used to calculate the percentage of impervious surface construction would affect, wetlands under the Coastal Area Management Act jurisdiction are excluded.

"Those are normally the wetlands that are directly adjacent to coastal water, and most people just call them coastal marsh," Reeder said. "All other wetlands can be included."

There was also controversy over a provision using 10,000 square feet of disturbance as a threshold for inclusion under the rules. That provision was removed for residential development outside a half mile of shell fishing waters.

Language was changed for inside a half-mile of shellfish waters to change the word disturbance - which could include work such as grading or planting a garden. Now it reflects "built-upon," or the actual area of new impervious surface.

"If you put down 10,000 square feet of built-upon area you are going to have to do some modest controls like cisterns or something like that to control the rooftop runoff from the first inch and a half of rain," Reeder said.

Residential development within a half-mile of the shellfish waters on land over an acre is subject to the state's stormwater permitting requirements.

Another change allows use of wet detention ponds for storm water control within a half-mile of shellfish waters.

The rules remain complex and Reeder said the regulations do not paint all properties with a broad brush.

"You really can't do that," Reeder said. "Basically, you have to look at your specific situation."