List each process area and space, then trace its ventilation, electrical area classification, gas detection, construction, and fire protection through the process, mechanical, electrical, and architectural drawings. AI can flag conflicts; the engineer of record and the authority having jurisdiction decide compliance.
What does NFPA 820 cover?
NFPA 820 is the Standard for Fire Protection in Wastewater Treatment and Collection Facilities. NFPA describes it as providing requirements for protection against fire and explosion hazards specific to wastewater treatment facilities and their associated collection systems.
NFPA’s official NFPA 820 page identifies the 2024 edition as current when checked on October 4, 2026. Confirm the edition, local amendments, and project scope that actually govern the work. The publisher’s newest edition does not establish local adoption.
Electrical work in classified areas connects to the NFPA 70 electrical guide, and digester gas handling may also involve the NFPA 54 fuel gas guide or the NFPA 69 guide. Record which document the owner, design criteria, and authority apply to each area.
Start from the process area list
Collect the process flow diagram, the list of process areas and rooms, the mechanical ventilation drawings and schedules, the electrical area classification plans, the gas detection drawings, the architectural plans with wall and separation information, the fire protection drawings, and the civil plans for pump stations and collection structures.
Note whether each space is enclosed, partially enclosed, or open, and whether it is normally occupied. The drawings should agree on those labels before anything else is compared.
Trace each process area through the set
| Review question | Sources to compare | Decision to record |
|---|---|---|
| Area list | Process flow diagram, room schedule, code summary | Reconcile the process areas and spaces named across documents. |
| Ventilation | Mechanical plans, fan schedule, sequences | Check that each area’s ventilation basis and equipment agree between schedule and plan. |
| Area classification | Electrical classification plans, mechanical plans, process drawings | Confirm the drawn classification for each area matches the ventilation and process assumptions it relies on. |
| Gas detection | Detection drawings, sequences, electrical plans | Identify areas where the sequence lists detection that the drawings do not show. |
| Construction and separation | Architectural plans, wall types, door schedule | Check that separations between classified and unclassified spaces are drawn the same way on each sheet. |
| Fire protection | Fire protection plans, specifications, civil plans | Confirm protection shown for each area agrees with the specifications and site water supply. |
Carry site and collection structures into the civil and site drawing checklist, ventilation into the mechanical drawing checklist, and utility work into civil and infrastructure project review.
Example: a ventilation change that the classification did not follow
Hypothetical example. A mechanical revision changes the ventilation basis for a headworks building, while the electrical classification plan still reflects the original basis and the gas detection drawings show detectors only in the old layout.
The mechanical drawings show a revised ventilation basis for the headworks building, but the electrical area classification plan and gas detection drawings reflect the previous one. Please confirm the ventilation basis and revise the classification and detection drawings as needed.
The mechanical and electrical engineers agree on the basis and revise their drawings. Whether the classification meets the adopted standard is the engineer’s and authority’s decision.
Review wastewater facility documents with Groundbook
Upload the current project PDFs and relevant specifications to Groundbook. Identify the governing issues and add the applicable NFPA 820 reference from a copy you are licensed to use, where the license permits uploading it. State the edition, amendments, review area, and known exclusions in your instructions.
Compare the process flow diagram, process area list, ventilation drawings and schedules, electrical area classification plans, gas detection drawings, architectural plans, fire protection drawings, and civil plans. Flag area labels, ventilation, classification, detection, separation, and protection information that differ between sources. Use the supplied NFPA 820 edition where applicable and cite both sources.
Groundbook links each potential finding to the sheets behind it. It does not decide how an area should be classified; it checks that the documents agree on the classification they state.
Document review does not classify hazardous areas, calculate ventilation rates, or approve the facility. Those decisions remain with the engineer of record and the authority having jurisdiction.