The two model ordinances offer different levels of "completeness" depending on the regulatory focus. The Sierra Club SPG ordinance (on this page) is more technically complete regarding operational performance and infrastructure impacts, while the PennFuture (Version 2.0) ordinance is more complete regarding land-use aesthetics and private well protection.

1. Air Quality and Emissions

• More Complete: Sierra Club
• The Sierra Club ordinance provides a highly detailed framework for emissions, mandating a Tier 4 Final standard for all diesel generators, regardless of their "emergency" status. It includes specific dispersion modeling triggers based on facility capacity or proximity to receptors and sets output-based limits (lb/MWh) for non-emergency operations.
• In contrast, PennFuture focuses primarily on screening backup equipment visually and for noise, without specifying engine emission tiers or detailed air impact modeling.

2. Noise and Vibration

• More Complete: Sierra Club (Technical Metrics); PennFuture (Time-Based Limits)
• Sierra Club is technically more robust, requiring one-third octave band analysis to detect low-frequency humming and applying a 5 dBA "tonal penalty". It also mandates permanent, continuous sound monitoring for facilities near sensitive receptors.
• PennFuture provides a more detailed regulatory table for noise limits, distinguishing between Daytime, Evening, and Nighttime hours across different zoning districts. It also includes extensive "Pure Tone" tables for evaluation.

3. Water Resource Management

• More Complete: PennFuture (Groundwater/Well Protection); Sierra Club (Cooling Technology)
• PennFuture excels in protecting local aquifers. It requires a 3,000-foot well-testing radius, detailed hydrogeologic studies, and a legal presumption that the operator is responsible for any adverse well impacts within 60 months of operation.
• Sierra Club is more complete regarding cooling efficiency. It mandates closed-loop cooling as the "bright-line" requirement and prohibits open-loop systems. It also requires reporting on Water Usage Effectiveness (WUE).

4. Power Quality and Grid Reliability

• More Complete: Sierra Club
• The Sierra Club ordinance is significantly more comprehensive in this area. It establishes strict Total Voltage Harmonic Distortion (VTHD) limits of 5.0% to prevent grid instability. It also requires a Reliability and Load Management Plan that dictates how a facility must curtail non-critical loads during grid emergencies.
• PennFuture only requires documentation from the utility provider certifying that sufficient capacity exists.

5. Communications and Public Safety

• More Complete: Sierra Club
• The Sierra Club ordinance includes an entire section dedicated to preventing interference with public safety radio systems (PA-STARNet) and mitigating cellular "shadowing" caused by large structures. It requires baseline and post-construction RF/EMI assessments by qualified professionals.
• PennFuture does not provide specific standards for communications interference or RF safety.

6. Siting and Aesthetics

• More Complete: PennFuture
• PennFuture provides more detailed landscape buffer requirements (25-foot width) with specific counts and sizes for evergreen and deciduous trees. It also mandates aesthetic design elements for building facades, such as material changes or step-backs every 150 feet.
• Sierra Club focuses on setbacks for high-impact components like generators but provides fewer prescriptive standards for building aesthetics.

7. Financial Security and Decommissioning

• More Complete: Sierra Club
• Both ordinances require a 110% decommissioning surety. However, the Sierra Club ordinance provides a more detailed escrow mechanism to ensure the municipality can hire independent experts for ongoing technical audits and complaint investigations.

Data Center Ordinance Scorecard for the Chester/Montgomery County Ordinance Guide (doc format, spreadsheet format)

Technical Analysis: Enhancing Chadds Ford Ordinance No. 184 for Long-Term Community Protection
While the proposed Chadds Ford Ordinance (Ordinance 184) adopts many industry-leading measures, a side-by-side comparison with the Data Center Model Ordinance (Draft v6.1) reveals several critical technical and procedural gaps. Addressing these "deficiencies" will ensure the Township is not only protected from immediate nuisances but also from long-term grid instability and fiscal cost-shifting.

1. Inadequate Noise and Acoustic Safeguards

• Permissible Decibel Levels: Ordinance 184 sets a maximum nighttime limit of 52 dBA at sensitive receptor property lines. The model ordinance establishes a significantly more protective nighttime cap of 40 dBA, noting that continuous industrial noise above this level is scientifically documented to cause sleep disruption and stress.
• Measurement Methodology: While Ordinance 184 identifies the nuisance of "Pure Tones," the model ordinance mandates one-third octave band analysis to capture low-frequency tonal impacts (the constant "hum") more accurately than standard dBA measurements.

2. Missing Numeric Power Quality Standards

• Harmonic Distortion: The model ordinance establishes clear, objective "bright-line" standards to protect the local grid from "flicker, sags, and swells". It mandates that Large-Load Data Centers (LLDCs) must not exceed a Total Voltage Harmonic Distortion (VTHD) of 5.0% and individual voltage harmonics of 3.0% at the Point of Common Coupling (PCC).
• Chadds Ford Gaps: Ordinance 184 requires a "Grid Impact Study" but fails to include these specific, numeric thresholds for harmonic distortion, leaving the definition of "grid integrity" open to subjective interpretation by utility providers.

3. Lack of Non-Combustion Energy Requirements

• Mandatory Capacity Floor: To fulfill the municipality's duty to conserve clean air under the Environmental Rights Amendment, the model ordinance requires LLDCs to provide a minimum of 20% of their total emergency backup power capacity through non-combustion technology, such as Battery Energy Storage Systems (BESS).
• Chadds Ford Gaps: Ordinance 184 mandates Tier 4 Final diesel engines but does not require any portion of the backup load to be served by cleaner, non-combustion alternatives.

4. Deficient Communications Resilience and Public Safety

• Predictive Assessments: The model ordinance requires a robust predictive assessment of RF/EMI emission and coupling pathways specifically addressing compatibility with public safety systems like PA-STARNet.
• Cellular "Shadowing" Mitigation: A key community protection in the model is the requirement for developers to mitigate "shadowing"—where the massive physical structure of the data center degrades neighborhood cellular coverage.
• Chadds Ford Gaps: Ordinance 184 only requires a general certification of FCC Part 15 compliance, missing these specific public safety resilience and neighborhood coverage mitigation protocols.

5. Absence of Electricity Rate and Fiscal Transparency

• Cost-Shifting Protections: The model ordinance includes a legislative finding that data centers receiving negotiated, below-market utility rates may shift infrastructure and transmission costs to other local ratepayers.
• Mandatory Disclosure: To evaluate the true net fiscal impact, the model requires applicants to disclose their effective electricity rate, rate schedule, and contract duration. This information is also used to verify that the developer has the long-term financial capacity to fund mandated environmental safeguards.
• Chadds Ford Gaps: Chadds Ford's "Impact Analysis" lacks these specific financial transparency requirements, leaving the Township unable to verify if the project is subsidized by local residents' utility bills.

6. Missing Resource-Efficiency KPIs and GHG Reporting

• PUE and WUE Monitoring: The model mandates annual reporting of Power Usage Effectiveness (PUE) and Water Usage Effectiveness (WUE). Crucially, it includes a "degradation trigger"—if efficiency worsens by more than 10%, the operator must submit a corrective action plan.
• Greenhouse Gas (GHG) Reporting: To align with Commonwealth climate goals, the model requires annual reporting of Scope 1 and Scope 2 GHG emissions in carbon-dioxide equivalents.
• Chadds Ford Gaps: Ordinance 184 does not require these standardized efficiency metrics or emissions reporting.

7. Loophole for "Bridge Power" and Temporary Units

• Prohibition on "Dirty Bridge Power": The model ordinance explicitly prohibits using any non-Tier-4 diesel generator for construction, commissioning, or early operations, rejecting "supply-chain delays" as a valid excuse.
• Chadds Ford Gaps: Ordinance 184 lacks explicit "bridge power" safeguards, potentially allowing for the operation of dirtier, temporary generators for extended periods prior to full utility service.
   

This report evaluates the Upper Merion Data Center Ordinance (the "Township Ordinance") in comparison to the SPG Data Center Model Ordinance (v7.4) While the Township Ordinance contains several strong localized protections, it lacks critical technical, financial, and legal safeguards found in the Model Ordinance that are necessary to mitigate the unique impacts of Large-Load Data Centers (LLDCs).

                               Upper Merion Data Center Ordinance Scorecard Report

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