Determination of Appropriate Monitoring Level(s) for a Stormwater Treatment Practice
Determination of Appropriate Monitoring Level(s) for a Stormwater Treatment Practice.
Link to this table
| Level | Should I perform this assessment? | Advantages | Requirements/limitations | Recommended frequency | Can this be used to obtain a stormwater credit? |
|---|---|---|---|---|---|
| Visual inspection | Recommended for all practices | Quick and cost-effective | Available personnel. Does not necessarily identify causes of poor performance. | ≥ 1x / year, at start of rainy season | No |
| Capacity testing | If there are suspected filtration rate problems with the practice, or to determine if the media has capacity for phosphorus removal | Applicable for practices of all sizes, quickly identify specific areas that require maintenance, less time and expense than monitoring | A Modified Philip-Dunne Infiltrometer is recommended for filtration rate testing. | Every few years | Consult with MPCA (Minnesota Pollution Control Agency) or regulatory agency to determine eligibility |
| Synthetic runoff testing | If there are suspected problems with filtration or pollutant removal, or to establish a baseline condition or baseline performance level | Controlled method to accurately measure drawdown time and/or pollutant removal efficiency |
|
Every few years | Consult with MPCA or regulatory agency to determine eligibility |
| Monitoring | Goals include obtaining stormwater credits, assessing performance results and life of filter media, or complying with a permit or regulatory agency | Most comprehensive assessment technique and measures the response to natural rainfall events |
|
Continuously from construction of the IESF | Yes |