DES MOINES, Iowa (AP) — A citizen activist group and an environmental organization have filed a petition asking the Iowa Department of Natural Resources to improve the state’s livestock farm permit process. Iowa Citizens for Community Improvement and Food & Water Watch say the permit system established 15 years ago fails to give local officials enough control over where large hog, cattle and chicken farms locate.

The petition filed Tuesday asks the DNR for several changes to the master matrix system including stricter pollution requirements and increased distance requirements from schools, homes, waterways and wells. County officials say permits they reject are nearly always approved by a state governor-appointed board. DNR records show only 2 percent of applications have been denied.

Iowa has 9,000 large-scale animal farms producing 22 billion gallons of manure a year.