Helena Sand & Gravel on Thursday filed a lawsuit in state District Court to protect its ability to expand operations at its new East Helena gravel pit.

The company last month got a permit to mine materials from a 111-acre plot on the site, but it had planned to eventually excavate the entire 440-acre parcel.

Citizen-initiated zoning regulations, approved by the Lewis and Clark County Planning and Zoning Commission on Thursday and set for county commission consideration July 10, would prevent the expansion.

The company claims the decision was arbitrary, capricious and unfairly targeted Helena Sand & Gravel’s operation and said the action has damaged its property value without compensation. The company asked the court to rule it has the right to mine the entire property.

The rules also would prevent the company from amending its permit, said attorney Michael Kakuk, who represents the firm — even when those amendments are aimed at addressing concerns raised by neighboring homeowners.

For instance, the company has been working to figure out a way to control dust after-hours at the site. The company may need to change its permit to allow workers onsite after 7 p.m. to do dust control, Kakuk said.

The gravel pit is located between Lake Helena and Valley drives and south of Canyon Ferry Road. Several subdivisions are located nearby.

In the lawsuit, Kakuk criticized the county’s assertion of the area’s residential nature and said five permitted or operating gravel pits exist in the surrounding area.

County Commissioner Mike Murray said he had not seen the lawsuit and could not comment. A call to a county attorney was not returned.

Reporter Larry Kline: 447-4075 or larry.kline@helenair.com