Data centers are prohibited in the unincorporated Flint Hills Ecoregion/Tallgrass Heartland and in unincorporated areas outside Butler County’s Urban Growth Area. Edge/Micro and Modular/Container facilities are exempt only if they are under 20,000 square feet, occupy less than 10 acres, use no water cooling, and do not expand without Board approval.

A conditional use permit is required to construct, expand, or operate a data center in the AG-40 or AG-80 zoning districts.

An applicant must submit a concept plan at least 60 days before the required pre-application meeting.

Applicants must attend a pre-application meeting with County planning, public works, emergency-management, and other designated staff before submitting a CUP application.

After submitting the application, the applicant must hold and pay for a community meeting before the Planning Commission hearing unless the Board expressly waives it. Certified-mail notice is required to property owners within 1,000 feet, cities and townships within 3 miles, and County officials, generally 21 to 30 days before the meeting.

A data center CUP application is incomplete until the required forms, fees, third-party review deposit, plans, studies, and technical reports are submitted. The County may request additional information, and the applicant must pay County-incurred third-party review costs beyond the deposit.

Applicants must submit a development plan and site plans showing items such as building locations, access, utilities, drainage, screening, lighting, project boundaries, development areas, buffers, and distances to noise-sensitive receptors. The final recommended draft also requires a separate utility-infrastructure site plan.

The application process may require numerous technical submissions, including landscape and screening, lighting, traffic, noise and vibration, utility feasibility, drainage, fire and life safety, hazardous materials, emissions, water use, construction management, security, emergency response, energy use, electronic waste, decommissioning, environmental and cultural resources, aviation, and fiscal-impact studies.

The Planning Commission must hold a public hearing and make a recommendation, and the Board must make the final CUP decision. The Board may approve, conditionally approve, deny, or return the recommendation; overriding the Planning Commission recommendation requires a two-thirds Board vote.

Projects must meet minimum site-area requirements based on their classification: generally 40 to 640 acres for hyperscale, 20 to 40 acres for colocation, 10 to less than 20 acres for enterprise, less than 10 acres for Edge/Micro, and less than 5 acres for Modular/Container facilities, unless the Board finds a smaller site adequate.

The cumulative Project Site for a data center project, including related phases, expansions, affiliates, and entities acting in concert, is capped at 640 contiguous acres. Projects may not be segmented or structured to evade this limit.

Hyperscale and colocation projects generally require a 250-foot buffer for principal buildings and truck idling, 250-foot setbacks for stand-alone mechanical and electrical facilities, 1,000-foot setbacks from residences and noise-sensitive receptors for those facilities, and a 150-foot setback from public rights-of-way. Building height is limited to 72 feet, subject to the stated variance provision.

Enterprise, Edge/Micro, and Modular/Container projects generally require a 35-foot buffer, 50-foot setbacks for stand-alone mechanical and electrical facilities, 75-foot setbacks from residences and noise-sensitive receptors for those facilities, and a 75-foot setback from public rights-of-way. Building height is limited to 35 feet.

Impervious surface is limited to 50 percent of the Project Site unless a stormwater analysis shows no adverse off-site impacts and the Board approves a higher percentage.

Data centers must comply with operational noise limits of 55 dB(A) and 60 dB(C) at night and 60 dB(A) and 65 dB(C) during the day, measured at the Project Boundary. The rules also require pre- and post-construction studies, full-spectrum and low-frequency analysis, and evaluation of tonal noise, amplitude modulation, and one-third-octave bands.

If noise limits are exceeded, the owner or operator must implement mitigation and retest within 90 days. Post-construction noise studies are required for each phase within 12 months after its certificate of occupancy.

Exterior lighting must be fully shielded and directed downward, must generally remain at or below 0.1 foot-candle at the Project Boundary, and must use controls such as timers, motion sensors, or dimming. Searchlights, laser lights, and other skyward-directed lighting are prohibited except for temporary emergency response.

Routine generator testing is limited to eight hours per generator per month and must generally occur from 9:00 a.m. to 3:00 p.m. Monday through Friday, excluding federal holidays. Load-bank testing expected to exceed two continuous hours requires 30 days’ advance notice.

Private groundwater wells and direct withdrawals from surface watercourses may not be used for a principal data-center use, including irrigation. Public water sources require certified documentation of available capacity, and proposed on-site wastewater systems require KDHE approval.

Data centers should use closed-loop water cooling. An alternative cooling technology must demonstrate equal or lower water consumption and equal or greater energy efficiency than a closed-loop system.

Stormwater facilities must prevent adverse off-site flooding and erosion, comply with KDHE requirements, and be maintained in perpetuity under recorded maintenance agreements, access easements, and an operations-and-maintenance plan.

Fuel tanks require secondary containment equal to at least 110 percent of the largest tank plus storm-event freeboard, must satisfy setback and floodplain requirements, and must be covered by spill-prevention and response procedures.

Owners must provide financial assurance for decommissioning and site restoration before the first building permit or other required milestone. The amount is based on an independent third-party cost estimate plus a 15 percent contingency, with updates generally required every three to five years and after each completed phase.

Decommissioning obligations may be triggered by 12 months of cessation of primary operations, abandonment, CUP revocation with an order to cease operations, or voluntary permanent shutdown. Financial assurance remains in place until the County confirms restoration is complete.

Owners or operators must submit annual compliance reports covering generator testing, permit violations and incidents, material infrastructure changes, water use, stormwater maintenance, and emergency contacts.

The County may conduct reasonable compliance inspections and require targeted noise, lighting, or other testing in response to documented bona fide complaints.

A CUP amendment and Planning Commission hearing are required for specified material changes, including increases above 5 percent in IT load or electrical demand, increases above 10 percent in generator count or capacity, fuel-storage increases above 15 percent, development-area increases, project-site expansion, increased building height, new principal uses, or changes creating new or increased off-site impacts.

A data center CUP expires if necessary building permits have not been issued within 24 months of approval unless the Board grants an extension for good cause. Phased projects must include a phasing plan, and development rights vest upon issuance of a building permit.

Transfers, sales, conveyances, or assignments of a CUP require written notification to the Board, payment of an adopted transfer fee, assumption of all CUP obligations by the transferee, and continued financial assurance for decommissioning and reclamation.

A CUP may be suspended or revoked by the Board for specified material misrepresentations, uncured material violations, imminent threats to public health or safety, or uncured failure to meet CUP standards. The rules generally require written notice, at least a 90-day cure period, a hearing, and a written factual determination, except when immediate action is justified by an imminent threat.

A conditional use permit (CUP) pathway allows data centers to be constructed, expanded, and operated in the AG-40 and AG-80 zoning districts, subject to the regulation’s review process.

Edge/Micro and Modular/Container data centers may be developed in otherwise excluded areas if they have less than 20,000 cumulative square feet, occupy less than 10 acres, use no water cooling, and receive Board approval before expanding.

The Board may grant written waivers for core application materials and specified plans, studies, technical reports, letters, reviews, or other required items.

Plans, studies, and technical reports may be required at the application, CUP, platting, or permitting stage identified in the County’s application package, and the County may not require them earlier than that specified stage.

Routine maintenance, replacement-in-kind, and interior upgrades that do not increase approved external impacts, capacity, or site disturbance may be approved administratively rather than through a new CUP amendment.

The Zoning Administrator may approve minor site-layout adjustments within the approved Development Area and landscaping substitutions with equal or better screening value through written administrative approval.

A CUP authorizes development up to the approved limits for Development Area, building height, electrical demand, generator capacity, fuel storage, water demand, and other approved characteristics; changes within those limits generally do not require a CUP amendment unless otherwise required.

Phased development is expressly allowed when the application includes a phasing plan, allowing construction and operation to proceed in successive phases.

A CUP generally remains valid as long as the use continues in compliance, and after a building permit is issued the CUP and associated development rights vest and remain valid in perpetuity unless abandoned or revoked.

The CUP runs with the land and may be transferred, sold, conveyed, or assigned through written notification to the Board, rather than requiring express Board approval, provided the transferee or successor assumes the same obligations and financial-assurance requirements.

Setbacks may be reduced along a common property line through a written agreement with the adjoining property owner, provided the agreement identifies the properties and reduced setback and is recorded with the Register of Deeds.

Generators, transformers, fuel systems, cooling equipment, switchgear, UPS systems, and similar equipment located within, attached to, screened by, or enclosed by a principal data-center building are treated as part of the principal building and are not subject to separate setback requirements.

The regulation expressly supersedes conflicting or more restrictive provisions of the Butler County Zoning Regulations for specified data-center height, setback, and vesting provisions.

The County may require off-site utility upgrades or cost participation where legally permissible and necessary to serve the project, allowing needed infrastructure improvements to be addressed through the CUP and separate utility agreements.