System maintenance would involve such items as cleaning influent and effluent channels, inspecting the berms for rodent holes and repairing them, and correcting short-circuiting in the ponds. All treatment plants should be monitored at least monthly to insure proper operation. Inspection protocols require the Department to sample discharges once per quarter. So, the additional cost to the Department will be 8 samples and analysis each year. The costs discussed above are best estimates and contain some uncertainty.
Prudent engineering adds a contingency amount to estimated costs to account for uncertainty.
A minimal impact postmining discharge is one that, untreated, does not result in a violation of the water quality standards of the receiving stream. If such data is inconclusive or unavailable, the operator must supply the data. A minimum of six upstream and downstream samples should be taken. This frequency coincides with the requirements for discharge sampling. The following process can be used to determine the stream impacts of an untreated discharge.