Imported from TapnTell-AI/awesome-legal-aiagent-skills (environmental-esg/draft-comment-letter-on-proposed-npdes-permit/SKILL.md). Install upstream with npx skills add TapnTell-AI/awesome-legal-aiagent-skills --skill draft-comment-letter-on-proposed-npdes-permit. Copyright stays with the author.

Skill: Draft Comment Letter on Proposed NPDES Permit

1. Subject-matter triage

• Treat the assignment as a formal regulatory comment submission, not a policy memo.
• Determine the permit status, receiving water, industrial category, and whether the record includes the current permit, fact sheet, monitoring data, TMDL materials, and any technical review.
• If only one proposed permit is at issue, state that plainly; if the record contains multiple permits, permit provisions, outfalls, waters, or pollutant groups, enumerate them before analysis and address each separately.
• Prioritize the operative permit terms first: effluent limits, monitoring, reporting, compliance schedules, special conditions, and fact sheet rationale.
• Draft the letter to oppose approval unless the record supports the permit under the governing Clean Water Act standards.

2. Failure modes the skill is correcting

• Drafts drift into generalized environmental advocacy instead of tying each objection to a specific permit deficiency and governing requirement.
• Drafts treat the letter as a narrative summary rather than a point-by-point legal submission grounded in the administrative record.
• Drafts omit comparison to the existing permit, causing missed anti-backsliding and antidegradation issues.
• Drafts ignore monitoring and reporting provisions even where the adequacy of limits depends on verification.
• Drafts make unsupported scientific assertions instead of using ambient data, receiving-water conditions, and technical review findings.
• Drafts state conclusions without naming the authority that supports them.
• Drafts fail to convert objections into concrete requested revisions, denial requests, or further review demands.
• Drafts bury the strongest issues; the letter should lead with the most legally significant and best-supported objections.

3. Legal frameworks / domain conventions that apply

• Clean Water Act NPDES permitting under 33 U.S.C. §§ 1311, 1312, 1313, 1314, and 1342, as implemented by EPA and delegated state permitting rules.
• Technology-based effluent limits and applicable effluent guidelines for the regulated industry category.
• Water-quality-based effluent limits where technology-based limits are insufficient to meet water quality standards.
• State water quality standards, including designated uses, numeric criteria, narrative criteria, and implementation procedures.
• Antidegradation requirements for maintaining existing uses and protecting higher-quality waters under the applicable state program.
• Anti-backsliding constraints on permit revisions that would relax limits or monitoring.
• TMDL consistency where the receiving water has an established load allocation or wasteload allocation.
• Mixing zone and dilution methodology only where the permit relies on them and the governing program authorizes them.
• Public participation requirements for notice, comment, and hearing requests under the applicable permit process.
• Administrative record review conventions: the fact sheet must explain the basis for each major term, and unsupported rationales are vulnerable.

4. Analytical scaffolds

• Start from the permit term, then test it against the controlling legal standard, then test the standard against the record.
• For each challenged term, use the same sequence:
  • identify the permit provision;
  • identify the legal source for the limit or condition;
  • compare the provision to the current permit, the fact sheet, and the supporting data;
  • explain why the term is insufficient, inconsistent, or inadequately justified;
  • state the specific revision requested.
• For each effluent limit:
  • determine whether it is technology-based, water-quality-based, or both;
  • verify that the limit is supported by the applicable guideline, model, calculation, or receiving-water analysis;
  • test whether the monitoring frequency and analytical method can actually demonstrate compliance.
• For any limit relaxation, apply an anti-backsliding comparison to the corresponding prior term and examine whether the record identifies a permitted exception.
• For any increase in loading or change in discharge configuration, examine whether antidegradation review was performed and whether the record supports the required protection analysis.
• For any receiving-water concern, connect ambient data, impairment status, designated uses, and pollutant behavior to the permit term at issue.
• For any TMDL issue, test consistency between the permit’s wasteload allocation and the applicable TMDL assumptions, endpoints, and implementation schedule.
• For each issue, close with:
  • the governing authority by name and section or part;
  • the specific factual deficiency in the permit record;
  • the practical consequence for water quality, compliance, or public participation;
  • the requested remedy, such as permit revision, additional analysis, or permit denial.
• Use an issue-by-issue structure rather than a generalized list of concerns.

5. Vertical / structural / temporal relationships

• Compare the proposed permit against the current permit term-by-term to identify relaxations, omissions, new conditions, and changed compliance pathways.
• Link the permit conditions to the fact sheet rationale; if the fact sheet does not justify a limit, condition, or monitoring design, flag the gap directly.
• Link receiving-water conditions upstream and downstream, when the record includes them, to show whether the proposed discharge will measurably affect the waterbody.
• Link effluent limits to associated monitoring and reporting obligations; a limit without a realistic verification mechanism is incomplete.
• Link special conditions to compliance deadlines and operational milestones so the letter can identify whether the schedule is realistic and lawful.
• Link the permit to any TMDL, watershed plan, or impairment listing in the administrative record to test whether the permit fits the broader regulatory framework.
• When multiple pollutants, outfalls, or receiving waters are implicated, keep the temporal and spatial relationships distinct; do not collapse them into one analysis.

6. Output structure conventions

• Write a formal public comment letter with standard letterhead elements, date, recipient, permit identifier, and a clear subject line.
• Open with a concise summary of opposition and the principal legal and technical defects.
• Use a defined severity scale at the top if the letter discusses multiple issues, and apply it consistently to each issue discussed.
• Organize the body as numbered issues, each with:
  • a short issue heading;
  • the governing authority;
  • the permit deficiency;
  • the supporting record evidence;
  • the consequence if uncorrected;
  • the requested action.
• Keep the tone formal, record-based, and exacting; avoid rhetorical excess.
• End with a distinct recommendations section that states the requested actions in imperative form, identifies the responsible permitting authority or applicant-facing reviewer, and ties each request to the comment deadline or permit decision milestone.
• If warranted by the record, include a request for a public hearing and explain why oral testimony or an expanded record is necessary.
• Conclude with a clear statement that the commenter opposes issuance of the permit as proposed unless the identified defects are corrected.