Applies to data centers constructed within Desha County’s unincorporated limits, requiring them to incorporate external noise-attenuation measures into their design and construction.

Before construction or operation, the owner and operator must notify every resident and affiliated homeowners’ association within a half-mile of the parcel, file proof of notice with the county clerk within 30 days, and notify the county judge of the proposed location.

Before construction, the property owner must obtain a baseline sound study from a third-party acoustic engineer, measuring sound at the property line in eight specified directions, including mitigation recommendations, and file the report with the county judge and clerk within 30 days after completion.

Before construction, the owner must consult a third-party architectural or design firm and prepare a noise-attenuation plan. The plan must include adequate mitigation measures, show all mechanical equipment, fully screen that equipment, and be submitted to the county judge and filed with the county clerk within 30 days after completion and before construction.

Additions, changes, and expansions of a data center must comply with the ordinance’s noise-attenuation requirements and must be designed and submitted to the county judge and filed with the county clerk within 30 days after completion of the applicable report.

After construction and before beginning operations, the operator must obtain a post-construction noise study by a third-party acoustic engineer while mechanical equipment operates at full capacity, measure the same eight property-line locations, and submit the report to the county judge and clerk within 30 days. Operations cannot begin unless the study demonstrates compliance.

Data center operators must conduct annual noise studies under the baseline and post-construction study requirements and file the results with the county judge and clerk within 30 days after the anniversary of the first sound-study report.

A data center may not produce external sound levels of 65 dBA or higher from 8 a.m. to 10 p.m. or 55 dBA or higher from 10 p.m. to 8 a.m., measured at the receiving property line by a third-party acoustic engineer.

Noise measurements must follow specified procedures, including restrictions on outdoor testing during winds over 15 miles per hour or unsuitable wet or temperature conditions, immediate calibration of the meter, placement at least four feet above the ground or reflective surfaces, multiple readings using the average result, and preparation of a detailed monitoring report.

Failure to comply with the noise limits, approved attenuation plan, study-filing deadlines, building-plan filing requirement, or any other ordinance provision is a violation; a data center must be compliant before commencing operations, or it may be subject to an injunction or stay preventing operation.

Violators may be charged with a misdemeanor and, upon conviction, fined $1,000 per specified offense, double that amount for a repeated offense, and $500 for each day a continuing violation remains. The county or a citizen may also seek injunctions and other legal or equitable remedies.

A data center must cease operations until it complies with the ordinance, implements the required noise-attenuation measures, and meets the applicable noise limits.

The noise-attenuation plan does not have to adopt every recommendation from the third-party acoustic engineer; it may use the measures that the architectural or design firm considers adequate for compliance, providing flexibility in how the data center is designed. The building plan is not required to adopt any or all of the noise attenuation recommendations

The ordinance establishes defined external-noise limits under which a data center may operate: below 65 dBA from 8 a.m. to 10 p.m. and below 55 dBA from 10 p.m. to 8 a.m., measured at the receiving property’s property line. 65 dBa or higher during the hours of 8 A.M. to 10 P.M. or 55 dBa or higher during the hours of 10 P.M. to 8 A.M.