Leavenworth County work session outlines strict draft rules for data centers and battery storage, tentatively OKs 65 dB property-line noise cap

Leavenworth County planning staff used a long work session to present draft countywide regulations for data centers and battery energy storage systems (BESS), laying out where those uses could locate, how large facilities would be defined, and a suite of site-level controls for protecting rural neighbors.

Staff emphasized these rules are regulatory text for use countywide, not an approval for a specific project. For large data centers the draft proposes a new planned industrial technology district that would be a by-right zoning category for campuses meeting minimum criteria. Smaller centers could be allowed through a special use permit (SUP) in certain planned business, mixed-use or industrial districts. Staff said only a handful of county sites (roughly three to five) are likely to meet the transmission and utility criteria for large centers.

Key proposals include a 400-contiguous-acre minimum for large-scale centers, single-story building footprints (height measured to the top of the parapet), mandatory development agreements to spell out site-specific penalties and monitoring, and baseline site studies (traffic, geotechnical, wetlands, water quality). On water use, staff encouraged closed-loop cooling systems but said the county cannot compel a water purveyor to guarantee rates; the draft would require a service letter from the purveyor and incorporate water and energy benchmarking into development agreements.

On power generation, planning staff said the draft explicitly excludes nuclear facilities: “We will not entertain nuclear components to those generations,” staff told the board, reflecting prior BOCC direction. The draft also requires third-party construction inspection, and staff said developers would pay monitoring costs for publicly accessible 24/7 sites that report ambient sound, water use and power metrics.

Noise standards drew extended debate. Staff initially described a 75 dB property-line baseline (a residential AC-level comparison) with a 10 dB automatic reduction when narrow-band/tonal components are present. After discussion about ambient conditions and cross-jurisdictional practice, staff proposed and the board tentatively agreed to a compromise that would cap property-line sound at 65 dB and drop to 55 dB where tonal components are detected; pre- and post-construction studies would establish site-specific baselines that could be addressed through the development-plan process.

Battery energy storage systems were treated both as ancillary to data centers and as standalone facilities. Draft rules would limit standalone BESS to sites near transmission lines and away from residential subdivisions, require emergency response and fire suppression plans, specify insurance and indemnity terms, and limit SUP approvals for some BESS uses to two-year permits (so evolving technology can be reassessed on renewal).

Staff also answered questions about utility upgrades: they said Kansas statute requires data centers to pay for transmission or service upgrades triggered by their projects. On reclamation, staff said full return to pre-development farmland is unlikely for very large facilities and that reuse or redevelopment is more probable; therefore, stringent development agreements are the preferred enforcement tool. Staff said revisions will be prepared and the draft is expected to return for a public hearing before the Board of County Commissioners in August.

Board members asked for further detail on tonal noise methodology, water-use protections, electromagnetic interference for batteries, and the technical definitions that separate small, medium and large centers; staff said those items and identified typographical edits will be corrected prior to public hearing.