Del. Code tit. 3 § 1401
No agricultural or forestal operation within this State which has been in operation for a period of more than 1 year shall be considered a nuisance, either public or private, as the result of a changed condition in or about the locality where such agricultural or forestal operation is located. For the purpose of this section, "agricultural operation" shall be defined as set forth in § 8141(a) of Title 10. In any nuisance action, public or private, against an agricultural operation or its principals or employees, including forestall activity, proof that the agricultural operation, including forestall activity, has existed for 1 year or more is an absolute defense to the nuisance action, if the operation is in compliance with all applicable state and federal laws, regulations, and permits. If the operation is in compliance with all applicable state and federal laws, regulations, and permits, it shall be presumed to be conducted in a manner consistent with good agricultural practice. No state or local law-enforcement agency may bring a criminal or civil action against an agricultural operation for an activity that is in compliance with all applicable state and federal laws, regulations, and permits.
3 Del. C. § 1401