Small Community Constructed Wetlands, Mound Systems
IDEM has coordinated review of permit applications for a few mound, constructed wetland wastewater treatment systems with the State Department of Health (ISDH). ISDH reviewed the construction and design plans for the systems consistent with their review for similar non-community systems. IDEM defers to ISDH's review of design and construction plans.
IDEM has subsequently drafted an operation permit [DOC]. These systems generally consist of a septic systems followed by constructed wetlands and mounds. The permit is in draft form and will soon be available on IDEM's website. We would appreciate your comments and suggestions. The following are some of the highlights of the Draft Operation Permit:
Monitoring
Monitoring is required both before and after the constructed wetlands
Frequency: Quarterly
Draft Parameters:
| Parameter | Limit |
|---|---|
| Influent | Flow |
| Effluent | Flow |
| PH | Report |
| CBOD5 | 25 mg/l |
| TSS | 30 mg/l |
| Total Kjeldahl N (TKN) | Report |
| Nitrate | 10 mg/l |
| Nitrite | Report |
| Ammonia Nitrogen | Report |
| Total N (TKN+NO3+NO2) | 10 mg/l |
Compliance
Compliance point is at the discharge from the constructed wetland
- In the event that limits are exceeded, the following must occur:
- Permittee must monitor again within 72 hours
- If results confirm that a limit is exceeded for any parameter, the permittee must do the following:
- Submit for approval a Corrective Action Plan (CAP)
- Implement the CAP
- Monitor Monthly until returning to compliance
- In the event of continued noncompliance, the Department may require a determination of the effect on groundwater or may require additional treatment.
Minimum Water Quality Requirements
Cannot cause the ground water in a drinking water supply well to have a contaminant concentration that creates any of the following:
- An exceedance of the numeric criteria for drinking water class groundwater
- Level that is acutely or chronically toxic, or otherwise injurious to human health
- Exceedance of:
- Chloride at 250 mg/l
- Sulfate at 250 mg/l
- TDS at 500 mg/l
- Total Coliform at nondetect
- Renders the well unusable
Operation, Maintenance, and Inspection
- Visual inspections of the constructed wetland and elevated sand mounds would be required monthly.
- Inspection of septic tanks once every two years.
- Reporting of the monthly inspections every quarter.
Other Provisions
- The permit requires the permittee to provide IDEM with an Operations and Maintenance Manual. The manual would include description of activities to be performed by the permittee as well as a conceptual Corrective Action Plan.
- The disposal site cannot be located within ½ mile of new or existing drinking water wells.
- A certified operator is required by this permit
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