# Stormwater MS4 compliance software that turns a year of small activities into the annual report

> Stormwater MS4 compliance is the work an operator of a municipal separate storm sewer system does to hold and keep NPDES permit coverage. A permitted small MS4 must run a written stormwater management program covering six minimum control measures, from public education to good housekeeping. The Phase I rule of 1990 covered systems serving 100,000 or more people and the Phase II rule of 1999 extended coverage to urban areas of 50,000 or more. Neurobird records the activity, the evidence and the measurable goal together.

- URL: https://neurobird.com/stormwaterms4/
- Product: Neurobird Stormwater MS4 Compliance Compliance Platform
- Niche: stormwater MS4 compliance
- Buyer: MS4 permit holders
- Status: in development, open for early access
- Updated: 2026-08-21

## What Neurobird Stormwater MS4 Compliance does

- Attach every activity to the minimum control measure and measurable goal it evidences
- Track outfall screening and illicit discharge investigations from report to resolution
- Log construction site and post construction reviews with the acreage that triggered them
- Assemble the annual report from the year that actually happened rather than from memory

## How it works

1. **Set up the measures** The six minimum control measures and your own measurable goals become the structure, so every activity has somewhere to land.
2. **Log the year as it happens** Outfall screenings, illicit discharge investigations, site reviews, training and outreach are captured with dates, people and evidence attached.
3. **Assemble the report** The annual report is built from the logged year, with each claim pointing at the record that supports it.

## From the source material

> The Muck Stops Here: Construction Site Erosion and Sediment Control Basics is a training tool that provides specific examples of effective practices seen at active construction sites.

Source: Ohio EPA, stormwater program, https://epa.ohio.gov/divisions-and-offices/surface-water/permitting/stormwater-program

## Industry context

- **100,000** The Phase I stormwater rule, promulgated in 1990, applied NPDES permit coverage to medium and large MS4s generally serving populations of 100,000 or greater, to construction disturbing 5 acres or more, and to ten categories of industrial activity. (source: US EPA, Stormwater Phase II final rule factsheet, https://www.epa.gov/system/files/documents/2023-09/EPA-Stormwater-Phase-II-Final-Rule-Factsheet-1.0-Overview.pdf)
- **50,000** The Phase II rule, promulgated in 1999, expanded the program to operators of MS4s in urban areas with a population of 50,000 or more people, and to operators of small construction sites. (source: US EPA, Stormwater Phase II final rule factsheet, https://www.epa.gov/system/files/documents/2023-09/EPA-Stormwater-Phase-II-Final-Rule-Factsheet-1.0-Overview.pdf)
- **6 measures** Each permitted small MS4 operator must develop a written stormwater management program describing how it will comply with six minimum control measures: public education and outreach, public participation, illicit discharge detection and elimination, construction site runoff control, post construction runoff control, and pollution prevention with good housekeeping. (source: US EPA, Stormwater Phase II final rule factsheet, https://www.epa.gov/system/files/documents/2023-09/EPA-Stormwater-Phase-II-Final-Rule-Factsheet-1.0-Overview.pdf)
- **64 FR 68722** The Federal Register citation for the Stormwater Phase II final rule. Two later actions matter as much in practice: the MS4 General Permit Remand Rule at 81 FR 89320 and the Small MS4 Urbanized Area Clarification at 88 FR 37994. (source: US EPA, Stormwater Phase II final rule factsheet, https://www.epa.gov/system/files/documents/2023-09/EPA-Stormwater-Phase-II-Final-Rule-Factsheet-1.0-Overview.pdf)
- **1 report** EPA's guidance on developing an MS4 program expects the annual report to carry the results of information collected and analysed, summaries of planned stormwater activities and any changes made, which is a year of evidence rather than a summary. (source: US EPA, developing an MS4 program, https://www.epa.gov/npdes/stormwater-discharges-municipal-sources-developing-ms4-program)

## Pricing

- Small MS4: $130 per permittee, per month
- Program: $340 per permittee, per month
- County or regional: $600 per permittee, per month

## Questions

### What is stormwater MS4 compliance?

MS4 stands for municipal separate storm sewer system. Compliance means holding NPDES permit coverage for stormwater the system discharges and running the program the permit requires. For a small MS4 that means a written stormwater management program describing how the operator will meet six minimum control measures.

### What are the six minimum control measures?

Public education and outreach, public participation and involvement, illicit discharge detection and elimination, construction site runoff control, post construction runoff control, and pollution prevention with good housekeeping. Phase II requires permits to state clear, specific and measurable requirements for each one.

### Which systems are Phase I and which are Phase II?

The Phase I rule, promulgated in 1990, covered medium and large MS4s generally serving populations of 100,000 or greater, construction disturbing 5 acres or more, and ten categories of industrial activity. The Phase II rule, promulgated in 1999, extended coverage to MS4s in urban areas with a population of 50,000 or more and to small construction sites.

### What does maximum extent practicable mean in practice?

It is the permit standard small MS4 programs are held to, alongside protecting water quality and meeting the water quality requirements of the Clean Water Act. In practice a permitting authority reads it through the measurable goals in your own stormwater management program, which is why those goals need evidence behind them.

### Does this replace our GIS or asset management system?

No. The pipe network and the asset register stay where they are. What lives here is the program record: activities, evidence, measurable goals and the annual report they add up to.

## Sources

- [US EPA, Stormwater Phase II final rule factsheet](https://www.epa.gov/system/files/documents/2023-09/EPA-Stormwater-Phase-II-Final-Rule-Factsheet-1.0-Overview.pdf)
- [US EPA, developing an MS4 program](https://www.epa.gov/npdes/stormwater-discharges-municipal-sources-developing-ms4-program)
- [California State Water Resources Control Board, municipal stormwater](https://www.waterboards.ca.gov/water_issues/programs/stormwater/municipal.html)
- [Ohio EPA, stormwater program](https://epa.ohio.gov/divisions-and-offices/surface-water/permitting/stormwater-program)

## Contact

- office@neurobird.com
- https://neurobird.com/