(1) All CSO sites shall achieve and at least maintain the greatest reasonable reduction, and neither cause violations of applicable water quality standards, nor restrictions to the characteristic uses of the receiving water, nor accumulation of deposits which: (a) Exceed sediment criteria or standards; or (b) have an adverse biological effect.

(2) This chapter may not negate specific CSO reduction projects, programs, and schedules that the department and a municipality have agreed upon before this chapter's effective date. However, the provisions of this chapter shall still apply.