<?xml version="1.0" encoding="UTF-8"?>
<sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">

  <!-- Core landing pages, industries, waste-streams, resources, EWC chapters -->
  <sitemap>
    <loc>https://symbioflows.com/sitemap-core.xml</loc>
    <lastmod>2026-11-07</lastmod>
  </sitemap>

  <!-- 661 canonical EWC pages: index, 109 categories and 551 six-digit codes -->
  <sitemap>
    <loc>https://symbioflows.com/sitemap-ewc.xml</loc>
    <lastmod>2026-11-07</lastmod>
  </sitemap>

  <!-- EWC chapter hub pages (/ewc/chapter/NN) - 16 chapters clearing the content gate -->
  <sitemap>
    <loc>https://symbioflows.com/sitemap-ewc-chapters.xml</loc>
    <lastmod>2026-08-23</lastmod>
  </sitemap>

  <!-- Material -> EWC reverse-lookup pages (/ewc-code-for/*) -->
  <sitemap>
    <loc>https://symbioflows.com/sitemap-materials.xml</loc>
    <lastmod>2026-07-02</lastmod>
  </sitemap>

  <!-- RCRA code, list and material-to-RCRA reverse lookup pages (/rcra/* and /rcra-code-for/*) -->
  <sitemap>
    <loc>https://symbioflows.com/sitemap-rcra.xml</loc>
    <lastmod>2026-11-07</lastmod>
  </sitemap>

  <!-- US state waste codes: TX form codes, CA waste codes, WA dangerous waste (/state-waste-codes/*) -->
  <sitemap>
    <loc>https://symbioflows.com/sitemap-state-waste.xml</loc>
    <lastmod>2026-07-07</lastmod>
  </sitemap>

  <!-- Basel Convention Y/A/B waste shipment codes (/basel/*) -->
  <sitemap>
    <loc>https://symbioflows.com/sitemap-basel.xml</loc>
    <lastmod>2026-07-07</lastmod>
  </sitemap>

  <!-- 2,324 UN Numbers (49 CFR 172.101) + 20 hazard-class pages + hub (/un-number/*) -->
  <sitemap>
    <loc>https://symbioflows.com/sitemap-un-number.xml</loc>
    <lastmod>2026-09-29</lastmod>
  </sitemap>

  <!-- Industrial-symbiosis SEO cluster: pillar, flagship, commercial anchors (/industrial-symbiosis*) -->
  <sitemap>
    <loc>https://symbioflows.com/sitemap-industrial-symbiosis.xml</loc>
    <lastmod>2026-08-21</lastmod>
  </sitemap>

</sitemapindex>