Connects Claude to the Plutocalc Designer REST API for sizing water and wastewater treatment systems. You get 15 tools covering the full engineering workflow: list available treatment models (activated sludge, stripping towers, biological systems), fetch calculation templates with required parameters, retrieve reference databases and unit conversions, run computations, and convert between JSON and Markdown formats for easier reading. Includes license credit checks and direct links to model manuals. Useful when you need to design treatment plants through conversation rather than clicking through engineering software. The MCP server is hosted at plutocalc.com, so no local setup required, though you can self-host from the GitHub repo if needed.