(1) Notwithstanding any other provision in this act or the rules promulgated under this act, the department shall not establish or enforce a limitation for sodium or chloride in a groundwater discharge permit that is more restrictive than the following:

    (a) 400 milligrams of sodium per liter.

    (b) 500 milligrams of chloride per liter.

    (2) Notwithstanding any other provision of this act or the rules promulgated under this act, the department shall not establish or enforce a limitation for sodium or chloride in groundwater that is more restrictive than the following:

    (a) 230 milligrams of sodium per liter.

    (b) 250 milligrams of chloride per liter.

    (3) Notwithstanding any other provision of this part or rules promulgated under this part, if a permittee discharges sodium or chloride, or both, into groundwater that migrates off of the property on which the discharge was made and that discharge directly causes the groundwater concentration of sodium or chloride, or both, to exceed the levels provided under subsection (2), the permittee shall do all of the following:

    (a) Initiate a sampling program approved by the department to monitor downgradient water supply wells for the levels of sodium or chloride, or both, in the water supply.

    (b) If the concentration of sodium in a downgradient water supply exceeds the level provided under subsection (2), the permittee shall provide and maintain, for each affected downgradient water supply, free of charge, a point-of-use treatment system approved by the department that will remove sodium from the water supply so as to be in compliance with the level provided under subsection (2).

    (c) If the concentration of chloride in a downgradient water supply exceeds the level provided under subsection (2), provide to each affected water supply owner a notice of aesthetic impact with respect to chloride levels.

    (4) Notwithstanding any other provision of this act, a permittee subject to the requirements of subsection (3) that complies with the requirements of subsection (3) is not subject to response activities under part 201 with respect to a discharge of sodium or chloride, or both, that is in compliance with the discharge level under subsection (1).