New fertilizer rules will be going into effect for a portion of York County to protect against groundwater contamination.
The Upper Big Blue Natural Resources District board voted 8-4 to adopt a milder version of an earlier proposal that would have required districtwide use of nitrogen inhibitors.
The inhibitors are chemicals that slow the rate at which anhydrous ammonia, a fertilizer, is broken down into nitrates. Experts say nitrates pose health hazards when they seep into groundwater supplies.
The new rules require the inhibitors only for fall fertilizer applications and only in one part of York County where nitrate readings exceed the federal standard.