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:a. the permittee must use the treatment system for the treatment of phosphorus in stormwater. Non-stormwater discharges must not be treated by this system; | :a. the permittee must use the treatment system for the treatment of phosphorus in stormwater. Non-stormwater discharges must not be treated by this system; | ||
− | :b. the treatment system must be contained within the conveyances and [https://stormwater.pca.state.mn.us/index.php?title=Structural_stormwater_Best_Management_Practices structural stormwater BMPs] of the MS4. The utilized conveyances and structural stormwater BMPs must not include any receiving waters; | + | :b. the treatment system must be contained within the conveyances and <span title="A stationary and permanent BMP that is designed, constructed and operated to prevent or reduce the discharge of pollutants in stormwater"> [https://stormwater.pca.state.mn.us/index.php?title=Structural_stormwater_Best_Management_Practices structural stormwater BMPs]</span> of the MS4. The utilized conveyances and structural stormwater BMPs must not include any receiving waters; |
:c. phosphorus treatment systems utilizing chemicals other than alum or ferric chloride must receive written approval from the Agency; and | :c. phosphorus treatment systems utilizing chemicals other than alum or ferric chloride must receive written approval from the Agency; and |
Alum or Ferric Chloride Phosphorus Treatment Systems. [Minn. R. 7090]
If the permittee uses an alum or ferric chloride phosphorus treatment systems, the permittee must comply with Section 23 requirements. [Minn. R. 7090]
The permittee's alum or ferric chloride phosphorus treatment systems must comply with the following:
The permittee's alum or ferric chloride phosphorus treatment systems must meet the following design parameters:
A designated person must perform visual monitoring of the treatment system for proper performance at least once every seven (7) days, and within 24 hours after a rainfall event greater than 2.5 inches in 24 hours. Following visual monitoring which occurs within 24 hours after a rainfall event, the next visual monitoring must be conducted within seven (7) days after that rainfall event. [Minn. R. 7090]
Three (3) benchmark monitoring stations must be established. Table 1 in Appendix A must be used for the parameters, units of measure, and frequency of measurement for each station. [Minn. R. 7090]
Samples must be collected as grab samples or flow-weighted 24-hour composite samples. [Minn. R. 7090]
Each sample, excluding pH samples, must be analyzed by a laboratory certified by the Minnesota Department of Health and/or the Agency, and:
In the following situations, the permittee must perform corrective action(s) and immediately notify the Minnesota Department of Public Safety Duty Officer at 1-800-422-0798 (toll free) or 651-649-5451 (Metro area):
If the permittee discovers indications of toxicity or measurements exceeding water quality standards that the permittee determines does not endanger human health, public drinking water supplies, or the environment, the permittee must report the non-compliance to the Commissioner as required in item 26.12. [Minn. R. 7001.0150, Subp. 3(L), Minn. R. 7090]
The permittee must submit the following information with the annual report. The annual report must include a month-bymonth summary of:
A record of the design parameters in items 23.13 through 23.15 must be kept on-site. [Minn. R. 7090]
Site-specific jar testing conducted using typical and representative water samples in accordance with the most current approved version of ASTM D2035. [Minn. R. 7090]]
Baseline concentrations of the following parameters in the influent and receiving waters:
The following system parameters and how each was determined:
The following site-specific procedures must be developed and a copy kept on-site: