(q) Nothing in this section shall be construed to increase or expand, change, eliminate, reduce or otherwise limit the liabilities or obligations of any water company that are set forth in any law, rule, regulation or order to the tenant of a dwelling unit who is receiving water provided to the building by the water company.
(r) Nothing in this section shall affect or impair the powers and duties of the department of environmental protection or the department of public health with respect to water supply under chapter 111.
(s) No charge for water usage may be imposed on the tenant of any dwelling unit in a public housing development pursuant to chapter 200 of the acts of 1948, chapter 667 of the acts of 1954, chapter 705 of the acts of 1966, or chapter 689 of the acts of 1974.
(t) The department of public health shall promulgate such additional regulations to the state sanitary code as it determines to be necessary to implement this section.