(plaintiff claimed that defendant had adopted zoning rules that barred mining of sand and gravel on plaintiff's property for which it had a permit to mine 110 acres and wanted to mine the remaining 311 acres; plaintiff's neighbors objected to mining and defendant adopted regulations to bar further mining; defendant classified area as rural residential in spite of fact that five gravel pits in area; court determined that gravel pits were nonconforming uses permitted under state law; growth policy allowed existing gravel pits, but not in area plaintiff wished to mine; court, however, determined that denial of plaintiff's permit could constitute regulatory taking requiring compensation; court affirmed as to zoning part of case, but reversed and remanded on taking issue).