Data centers are permitted only with an approved Development Plan and only in the Planned Business Park (PB) or Planned Industrial (PI) zoning districts.

The data-center standards apply to new facilities and major expansions, defined as an increase of at least 10% in building area or utility demand.

Where the data-center standards conflict with other County regulations, the more restrictive requirement applies, and the County may impose additional or stricter standards on individual projects.

An Environmental and Community Impact Analysis is required before regulatory consideration and before any public hearing, covering operations, traffic, materials, utilities, public services, environmental impacts, and mitigation measures.

The environmental analysis must be reviewed by a Missouri-certified professional environmental engineer selected by the County, with all review costs paid by the applicant.

Applicants must provide site-plan information identifying floodplains, wetlands, and cultural or historic resources on the property and within 500 feet of its boundaries.

Development is prohibited in regulated floodplains and floodways, even if the area is later removed from that classification through a regulatory process.

Buildings are subject to maximum height limits of 50 feet in the Urban, Suburban, and Rural Growth Areas, with rooftop equipment allowed to exceed the applicable height by no more than 10 feet when fully screened.

Principal structures must be set back 200 feet from non-residential property and 1,000 feet from residentially developed property; the Director may reduce the residential setback only for unique topography or other natural conditions.

Accessory structures, including generators and utility substations, must be located behind the rear building plane of the associated principal structure and away from primary-facing facades.

Parking lots must be set back at least 150 feet from adjoining non-residential property and 950 feet from adjoining residentially developed property.

Utility substations must be set back at least 300 feet from all adjoining property lines.

Data-center sites must provide buffer yards, including a minimum 150-foot buffer along street frontages and property lines abutting or within 500 feet of residential property, schools, daycares, hospitals, places of worship, parks, or public open space.

A minimum 50-foot buffer yard is required along property lines adjacent to non-residential uses or zoning districts, and required buffers must include specified trees and shrubs designed to provide a complete visual screen within three years.

Ground-mounted mechanical equipment is prohibited in required setbacks and generally must be screened by an opaque wall or fence at least 10 feet high.

Chain-link fencing, including fencing with slats or other site-proofing measures, is prohibited; barbed wire is also prohibited within 200 feet of a public road or residence except when deemed necessary for security.

Principal buildings must meet detailed architectural requirements, including massing elements, facade treatments, window coverage, multiple visible building materials, restricted exterior colors, and limits on reflective surfaces and light trespass.

A lighting and photometric plan prepared and sealed by a qualified professional is required, with illumination limited to 0.1 foot-candles at adjoining residential properties and 0.5 foot-candles at other adjoining non-residential properties.

Site lighting must comply with Dark Sky and Illuminating Engineering Society standards, use fully shielded downward-directed fixtures, use LED lighting with a correlated color temperature no higher than 3000K, and use poles no taller than 20 feet.

Parking-area and vehicular lighting must generally be extinguished within 30 minutes after facility closing; after-hours safety lighting is limited to 25% of regular-business-hour fixtures, subject to specified exceptions for continued nighttime activity.

Motion sensors or adaptive dimming are required for non-security lighting, and timers must reduce nonessential lighting after business hours.

Annual lighting-compliance certifications, corrective action after light-spill complaints, and third-party testing are required at the owner or operator's expense.

Noise from equipment may not exceed 55 dBA and 65 dBC during the day or 50 dBA and 60 dBC at night at property lines adjoining residential, institutional, or qualifying agricultural property; the limits may be 5 dB higher for other non-residential property.

Tonal, impulsive, or rhythmic noise is treated as 3 dBA louder than its actual measurement for enforcement.

Before a construction permit is issued, applicants must submit a three-dimensional acoustic model using ISO 9613-2 or equivalent methodology, including worst-case summer and nighttime conditions, impacts at property lines and residences, and quantified mitigation measures.

The County may require peer review of acoustic modeling at the applicant's or owner's expense, and post-occupancy testing by an independent acoustical engineer is required within 60 days after full occupancy and operation.

Permanent sound-monitoring stations and annual noise-compliance certifications are required near adjoining properties, with monitoring results made available for public inspection.

Emergency generators may operate only during emergencies or scheduled testing; testing is limited to weekdays from 10:00 a.m. to 4:00 p.m., may not exceed 60 minutes per generator per month, and may not be conducted under load.

Emergency generators must be enclosed in sound- and emission-attenuating housings or buildings achieving at least a 25 dBA reduction.

A Utility Capacity Letter must establish sufficient grid capacity, no adverse effects on residential electric customers, required transmission or substation upgrades, and the schedule for those upgrades.

Data centers must participate in available demand-response programs, manage cooling loads during peak periods, and provide load-shedding plans for emergencies.

The developer must bear the reasonable and proportionate costs of required substation, transmission, and distribution-system improvements.

At least 40% of annual electricity consumption must come from renewable sources or qualifying renewable-energy programs at occupancy and annually thereafter; after five years, the requirement increases to 60%, subject to a documented technical-infeasibility exception and County-approved extension.

Emergency generators must meet EPA Tier 4 Final standards and may not be used for peak shaving, grid-power reduction, or market financial-incentive programs.

Applicants must evaluate onsite battery energy storage as the first option for power continuity and provide documentary justification if battery systems are deemed insufficient.

Water must come from the applicable public water district; use of private wells outside the public water-supply district's control is prohibited.

Applicants must disclose cooling technology and maximum daily water demand, use the most water-efficient available cooling technology, and may not use once-through water-cooling systems.

Applicants must obtain public-water-supplier verification of adequate source, treatment, and distribution capacity, and must fund or construct needed infrastructure expansions without burdening existing users.

Facilities must report monthly water consumption for the first three years or until stable operations are verified and provide annual certification of water-supply and cooling-efficiency compliance.

A wastewater impact assessment by a qualified Missouri-licensed engineer is required, including projected flows, chemical composition, discharge temperature, sewer impacts, and pretreatment systems.

Process wastewater must meet specified pretreatment limits for total dissolved solids, chlorides, pH, temperature, chemical additives, and heavy metals; the County may require additional treatment or zero-liquid-discharge systems.

Cooling-tower blowdown may not exceed 1,000 mg/L total dissolved solids, 250 mg/L chloride unless treated, or 104 degrees Fahrenheit, and prohibited biocides and other discharges may not interfere with wastewater treatment.

Facilities must install wastewater monitoring equipment and submit semiannual reports documenting discharge volumes, chemical analyses, temperatures, and pretreatment performance.

An air-quality impact assessment is required, and the County may require modeling of particulate matter, nitrogen oxides, sulfur dioxide, volatile organic compounds, and greenhouse gases.

Cooling equipment must use refrigerants with a global-warming potential below 750, and operators must maintain leak-detection, reporting, and corrective-action procedures.

A Stormwater Management Plan is required, and the County may require third-party engineering review at the applicant's expense.

Post-development peak runoff must be lower than pre-development runoff for the 1-, 2-, 10-, 25-, and 100-year storms, and the first 1.5 inches of rainfall must be captured onsite.

Stormwater best-management practices must receive semiannual third-party inspections selected by the County and paid for by the developer; failed or degraded systems may be required to be repaired, retrofitted, or replaced at the owner's expense.

Generators, transformers, fuel tanks, and associated piping must have secondary containment holding at least 110% of the largest vessel's capacity plus precipitation from a 25-year, 24-hour storm.

Cooling-tower blowdown, fire-system test water, HVAC condensate unless approved, treated process water, and water-softener brine may not enter the stormwater system.

Applicants must submit a Fire Water Management Plan addressing containment and disposal of firefighting runoff and fire-suppression test water; uncontrolled discharge to stormwater infrastructure is prohibited.

Before operations begin, the owner or operator must submit a decommissioning and site-remediation plan covering equipment removal, hazardous materials, contamination cleanup, site restoration, costs, and timing, with updates at least every five years.

Decommissioning must begin within 90 days after closure and generally must be completed within 12 months, unless the County grants an extension for good cause.

Before a certificate of occupancy, the owner or operator must provide financial assurance, such as a bond, letter of credit, or cash escrow, equal to 100% to 125% of the County-approved decommissioning and remediation cost.

A Development Agreement is required for every new data-center development and expansion, must be incorporated into the Development Plan approval, and remains effective for the life of the facility or 30 years, whichever is longer.

Development Agreement obligations run with the land, bind successors and assigns, apply by development phase, and may be enforced through modification or revocation of approvals.

The Development Agreement requires an annual infrastructure-impact payment to the County, indexed annually to the Consumer Price Index, plus an upfront payment before the first building receives a certificate of occupancy.

The developer must fund or construct required roads, intersections, signals, utility improvements, and public-safety equipment or training without imposing the costs on existing utility customers.

The Development Agreement requires a good-faith effort to use at least 25% Jefferson County construction labor hours and additional labor from the St. Louis metropolitan region, requires registered apprenticeships where available, requires prevailing wages, and requires submission of a Project Labor Agreement before the first building permit.

During operations, the developer must partner with Jefferson College and local high schools for workforce development, offer internships or training, and achieve at least 50% Jefferson County residency for full-time employment positions and labor hours.

The developer must fund an annual Community Grant Program supporting STEM education, community facilities and nonprofits, youth mental-health programs, and income-based socioeconomic grants for County residents.

Operators must submit annual certifications for noise, lighting, and water compliance, updated generator-testing schedules, and consumption data when requested; violations may result in abatement orders, penalties, civil enforcement, and utility disconnection.

Data centers are expressly authorized in Planned Business Park and Planned Industrial zoning districts through an approved Development Plan.

The maximum building height is increased to 80 feet in the Urban Growth Area and 70 feet in the Suburban Growth Area; the Rural Growth Area limit remains 50 feet.

Rooftop equipment may extend up to 10 feet above the applicable building-height limit when it is completely screened as required by the ordinance.

The required setback from residentially developed property is reduced from 1,000 feet to 500 feet for principal structures, and the parking-lot setback is reduced from 950 feet to 450 feet.

The Director may reduce required setbacks when adjoining property has unique topography or other natural conditions that mitigate the setback requirement.

Development Agreement requirements may be modified by mutual agreement between the County and the developer.

A Development Agreement must be acceptable to both the applicant and the County, allowing the applicant to withhold agreement from terms it does not accept.

A Development Agreement can remain effective for the life of the facility or 30 years, whichever is longer, and can apply by phase as the project develops.

Data centers are permitted only in Planned Business Park (PB) and Planned Industrial (PI) districts and require an approved Development Plan; the zoning matrix classifies them as permitted only under an approved plan.

The standards apply to new facilities and major expansions, defined as an increase of at least 10% in building area or utility demand.

Applicants must submit an Environmental and Community Impact Analysis before regulatory consideration and any public hearing, covering operations, traffic, materials, public services, environmental effects, and mitigation.

The environmental analysis must be reviewed by a County-selected Missouri-certified environmental engineer, with all review costs paid by the applicant.

The County may impose additional, stricter, or supplementary standards on individual developments, and the more restrictive requirement controls when regulations conflict.

Data center campuses must connect to public water and public sewer utilities.

Development is prohibited in all regulated floodplains and floodways, even if the property is later removed from the regulatory classification.

Data centers must provide buffer yards and screening along property boundaries, including a minimum 150-foot buffer along street frontages and along boundaries abutting or within 500 feet of residential properties, schools, daycares, hospitals, places of worship, parks, or public open space, plus a 50-foot buffer beside nonresidential uses.

Enhanced buffers adjoining residential uses or collector-or-greater roads require a planted earthen berm at least six feet high, with a maximum 2:1 slope.

Required landscape buffers impose substantial planting, screening, native-species, maintenance, and visual-screening requirements, including specified numbers and minimum sizes of evergreen trees, canopy trees, ornamental trees, and shrubs.

Principal structures must meet large setbacks: 200 feet from nonresidential property lines and 500 feet from residentially developed property with more than one dwelling unit per two acres, subject to a limited topography-based reduction by the Director.

Parking lots must be set back at least 150 feet from nonresidential property lines and 450 feet from qualifying residential property lines.

Accessory structures, including generators and substations, must be located behind the rear building plane of the associated principal structure and may not be placed in required setbacks.

Utility substations must be set back 300 feet from adjoining property lines and must have year-round opaque landscaping or a fully opaque screen wall at least 10 feet high.

Data center buildings are subject to maximum heights of 80 feet in urban growth areas, 70 feet in suburban growth areas, and 50 feet in rural growth areas; rooftop screens and parapets may extend no more than 10 feet above the structure.

Buildings and equipment must satisfy detailed architectural, façade, massing, material, color, entrance, window, and screening requirements, including limits on prohibited materials and requirements for differentiated design elements.

Chain-link fencing is prohibited, barbed wire is restricted and barred within 200 feet of public roads or residences, and only specified decorative fencing types are acceptable.

Exterior lighting requires a professionally prepared photometric plan, Dark Sky and IES compliance, LED fixtures with a maximum 3000K color temperature, maximum lighting levels of 0.1 foot-candles at residential properties and 0.5 foot-candles at nonresidential properties, automatic controls, and annual compliance certification.

Parking and traffic-area lighting must automatically shut off within 30 minutes after facility closing; after-hours safety lighting is limited to 25% of regular fixtures, subject to specified exceptions for dimming or motion controls.

Noise from equipment is limited at property lines to 55 dBA daytime and 50 dBA nighttime, with corresponding low-frequency limits of 65 dBC and 60 dBC; limits may be increased by 5 dB only beside certain nonresidential properties, and tonal or rhythmic noise is treated as 3 dBA louder.

Before construction permits, applicants must provide three-dimensional acoustic modeling for worst-case conditions, including impacts at property lines and nearby residences; County-required peer review is at the applicant's expense.

Facilities must conduct post-occupancy noise testing within 60 days of full occupancy, publicly post the results, install permanent sound-monitoring stations, and submit annual compliance certifications.

Emergency generator testing is limited to weekdays from 10 a.m. to 4 p.m., excluding holidays; testing is capped at 60 minutes per generator per month, simultaneous testing is prohibited, and generators may not be tested under load.

Generators must be enclosed in sound- and emission-attenuating housings or buildings achieving at least a 25 dBA reduction, and the energy provisions require EPA Tier 4 Final generators.

Permit applications must include a Utility Capacity Letter confirming adequate grid capacity, no adverse effects on residential electric customers, required transmission or substation upgrades, and upgrade timelines.

Operators must participate in available demand-response programs, manage cooling loads, provide load-shedding plans, and pay the reasonable and proportionate costs of required substation, transmission, and distribution upgrades.

At least 40% of annual energy consumption must come from renewable sources upon occupancy and annually thereafter, increasing to 60% within five years unless the County approves an extension based on documented technical infeasibility and qualifying circumstances.

Battery energy storage systems must be evaluated as the first option for power continuity; if found insufficient, the applicant must document the reasons.

Water must be obtained from the applicable public water district rather than an unregulated private well, and applicants must disclose cooling technology and maximum daily water demand.

Liquid-cooled, closed-loop cooling with limited evaporation is required unless a more water-efficient technology is available; once-through cooling is prohibited.

Applicants must obtain verification of adequate public water supply, treatment, and distribution capacity and must fund or construct needed water infrastructure without burdening existing users.

Facilities must report monthly water consumption for the first three years or until stable operations are verified and provide annual certifications regarding water, wastewater permits, and cooling-efficiency commitments.

Applications must include a licensed-engineer Wastewater Impact Assessment addressing flows, chemical composition, temperature, sewer impacts, and pretreatment systems.

Process wastewater must meet pretreatment limits for TDS, chlorides, pH, temperature, chemical additives, and heavy metals; the County may require additional treatment such as filtration, reverse osmosis, flow equalization, or zero-liquid discharge.

Cooling tower blowdown is limited to 1,000 mg/L TDS unless approved, 250 mg/L chloride unless treated, and 104 degrees Fahrenheit; prohibited biocides and certain high-salinity discharges are barred.

Facilities must install wastewater monitoring equipment and submit semiannual reports on discharge volumes, chemical analyses, temperatures, and pretreatment performance; County-required third-party audits are at the owner's expense.

Applicants must submit an approved Stormwater Management Plan with hydrologic modeling, BMP designs, outfalls, high-risk equipment areas, and construction phasing information.

Stormwater systems must reduce post-development peak runoff below pre-development rates for specified storm events and capture the first 1.5 inches of rainfall on site through infiltration, bioretention, or equivalent BMPs.

BMPs require at least semiannual third-party inspections, annual functionality certifications, and possible repair, retrofit, or replacement at the owner's expense; County-selected inspection or review costs may be charged to the developer.

Generators, transformers, fuel tanks, and associated piping must have secondary containment sized for 110% of the largest vessel plus precipitation from a 25-year, 24-hour storm, with impermeable surfaces, shutoff systems, and oil-water separation.

Cooling blowdown, fire-test water, most HVAC condensate, treated process water, and water-softener brine may not enter the stormwater system, and firefighting runoff must be captured and managed under an approved Fire Water Management Plan.

Operators must submit annual certifications for noise, lighting, and water compliance, updated generator-testing schedules, and consumption data upon request; complaints trigger County investigation.

Violations may result in abatement orders, penalties, and utility disconnection for a prescribed period; a court may impose civil penalties of up to $1,000 per day under the clean draft.

Before operations begin, owners must submit and periodically update a decommissioning and site-remediation plan covering equipment removal, hazardous materials, contamination remediation, restoration, costs, and timing.

Decommissioning must begin within 90 days after closure and generally be completed within 12 months.

Before receiving a certificate of occupancy, the owner must provide financial assurance, such as a bond, letter of credit, or cash escrow, equal to 100% to 125% of the County-approved decommissioning and remediation cost and keep it current.

The County may draw on the financial assurance, enter the property for inspections, revoke permits, and impose civil penalties if closure or remediation requirements are not met; ownership transfers do not automatically eliminate the original owner's responsibility.

The January 30, 2026 draft requires a Community Benefit Agreement for new data centers and expansions, incorporated into zoning or development approval and effective for the facility's life or 30 years, whichever is longer.

The proposed Community Benefit Agreement requires an agreed annual payment indexed to CPI-U, a negotiated upfront payment before the first building's certificate of occupancy, and possible minimum-revenue guarantees and clawbacks related to tax incentives.

The proposed Community Benefit Agreement requires workforce commitments, including targeted Jefferson County construction and operations labor participation, registered apprenticeships where available, prevailing wages, a Project Labor Agreement before the first building permit, and partnerships with Jefferson College and local high schools.

The proposed Community Benefit Agreement requires the developer to fund or construct needed roads, intersections, signals, public-safety equipment and training, and utility upgrades without charging existing customers.

The proposed Community Benefit Agreement requires an annual Community Grant Program supporting STEM education, community facilities and nonprofits, youth mental-health programs, and income-based grants for County residents.

A Development Agreement may be required to address additional adverse impacts not covered by the regulations or approved Development Plan.

Data centers are authorized as a permitted use by approved development plan in the Planned Business Park (PB) and Planned Industrial (PI) zoning districts.

The standards apply to new facilities and major expansions involving at least a 10% increase in building area or utility demand, so smaller expansions are outside the article's applicability.

Accessory data-center uses may be located on the same unified tract, including administrative and logistical buildings, generators for temporary emergency power, substations, utility lines, cooling systems, water and wastewater facilities, pump stations, fire-suppression equipment, and security structures. Energy-generation systems intended to supply normal operations are excluded.

Rooftop equipment may exceed the applicable district height limit by up to 10 feet when it is completely screened as required by the regulation.

Cooling towers may be mounted on roofs if the applicant demonstrates that the roof-mounted design provides equal or superior noise performance.

Existing vegetation may be used in place of new berms and plantings for required screening when approved by the Director of County Services.

For adjoining non-residential properties, the applicable daytime and nighttime noise limits may be increased by 5 decibels.

If continued nighttime activity requires site-wide illumination, the operator may use dimming that reduces illumination by at least 50% after 11 p.m. or after regular business hours, or may use motion-sensor controls instead of fully extinguishing the lighting.

The renewable-energy requirement allows a compliance extension when the applicant proves technical infeasibility and the County approves an extension based on documented extenuating circumstances; financial considerations alone do not qualify.

Buildings in the same development may be clustered so their primary entrances face internal parks, open spaces, infiltration areas, ponds, bioswales, or trails instead of an adjacent street or parking area.