(a)    Except as otherwise prohibited in subsection (b) of this section, the Department may issue a permit that allows the use of chlorine or chlorine compounds in treatment of wastewaters discharged from any publicly or privately owned sewage treatment plant to any surface waters of this State only if the treatment of the wastewaters includes dechlorination.

(b)    (1)    This subsection is not effective unless matching federal funds are available to implement the provisions of paragraph (4) of this subsection.

(2)    This subsection does not apply to sewerage treatment facilities that discharge an amount of treated sewage less than 1 percent of the 7-day, 10-year low flow of the receiving stream.

(3)    The Department may not issue a permit that allows the use of chlorine or chlorine compounds in the treatment of wastewaters discharged into any waters of this State that are designated by the Department as natural trout waters and their tributaries.

(4)    (i)    This subsection applies to any local subdivision that owns or operates an existing treatment system that is required to convert from use of chlorination to another system in order to be permitted under this subtitle.

(ii)    If the local subdivision applied for assistance from the Environmental Protection Agency on or before September 30, 1981, the conversion costs not funded by the Environmental Protection Agency may be covered with State funds as provided in the State budget.

(iii)    If the local subdivision failed to apply for assistance from the Environmental Protection Agency on or before September 30, 1981, conversion costs ordinarily met by the Environmental Protection Agency and this State shall be the responsibility of the local subdivision.