Editing Openai/68503d6e-9400-800b-a15a-dd25d536e24f (section)

=== Assistant: Planning and zoning norms for high-voltage transmission lines especially those over 230 kV generally draw on a combinat… ===
Planning and zoning norms for high-voltage transmission lines (especially those over 230 kV) generally draw on a combination of state utility commission standards, industry engineering guidelines, federal environmental and energy agency guidance, and case law precedent. However, there is no single uniform source. Here's a structured overview of the most widely used and cited authorities:

==== 📘 Primary Sources for Planning & Zoning Setbacks over 230 kV ====

===== 1. NESC (National Electrical Safety Code) =====
* Published by the IEEE, this sets minimum clearance and safety distances for power lines and structures.
* Defines vertical and horizontal clearance from the ground, buildings, and other structures for different voltages.
* Not zoning law, but adopted by many states and used to establish technical baselines.

: 🧩 Example: NESC Rule 232 defines minimum clearance of 23–30 feet from conductors to ground depending on voltage and environment.

===== 2. ANSI / IEEE Guidelines =====
* IEEE 738, 1243, 656 and other standards cover thermal, structural, and EMF field evaluations for transmission line design.
* Used by utility engineers and often incorporated into utility easement or right-of-way design documents.

===== 3. State-Level PUC Siting Guidelines =====
* For example: - Texas: PUCT uses a routing process (16 Tex. Admin. Code §25.101) requiring evaluation of proximity to residences, habitable structures, and environmentally sensitive areas, but does not impose specific setbacks. - Other states like California, Minnesota, and Virginia issue routing handbooks or recommend setback buffers (e.g., 300 ft+ for 500 kV lines).

===== 4. U.S. EPA & WHO Guidance on EMF =====
* The EPA and World Health Organization (WHO) have issued summaries of EMF research. While they stop short of setting mandatory buffers, some local zoning authorities adopt these to justify 300–500 ft setbacks.

===== 5. County/Local Zoning Codes =====
* Most actual setback rules come from local ordinances, informed by the above.
* Example: Some counties prohibit siting >230 kV lines within 300 feet of homes or schools unless special conditions are met.
* These vary widely and often defer to public comment, land use compatibility studies, or environmental impact assessments (EIAs).

===== 6. Case Law & Legal Precedent =====
* Texas courts have upheld that visual blight, EMF concern, and marketability justify compensation or restrictions.
* These cases indirectly guide local planners and attorneys in recommending larger setbacks for major lines.

==== 🔍 Sample Local Zoning Practices (Non-Binding but Common) ====

| Voltage    | Typical ROW Width | Common Informal Setback (homes) |
| ---------- | ----------------- | ------------------------------- |
| 230 kV     | 100–150 ft        | 150–300 ft                      |
| 345 kV     | 150–200 ft        | 300–500 ft                      |
| 500–765 kV | 200–250 ft        | 500+ ft                         |

These are often cited in local planning board documents, conditional use permits, and county transmission siting policies.

==== ✅ Takeaway ====

There’s no single national zoning law setting a fixed distance, but planners rely heavily on:
* NESC and IEEE safety and clearance codes
* PUC environmental criteria and routing standards
* EPA/WHO EMF summaries
* Local zoning precedent and community standards

If you're pushing for greater setbacks in your PUCT intervention, citing these sources (especially PUCT Rule §25.101, NESC Rule 232, and local zoning analogs) will make your case more persuasive.

Would you like a one-page summary PDF of these authorities to include in a formal filing or community presentation?