(1) TREATMENT.
(a)
Incineration or thermal
destruction. Incineration or thermal destruction of foam shall be
conducted at a temperature range and residence time sufficient to destroy PFAS
while also ensuring the maximum degree of reduction in emission of PFAS,
including elimination of emissions of PFAS when achievable. Prior to any person
operating an incineration or thermal destruction treatment system under this
subsection, a person shall submit documentation to the department that
demonstrates the incineration or thermal destruction treatment system meets all
of the requirements of this paragraph.
Note: Any discharge of treated foam to a
sanitary sewer requires the approval from the owner of the publicly owned
treatment works and may be subject to additional limitations. Any discharge of
treated foam to waters of the state, including a discharge of treated foam
through a storm sewer, requires Wisconsin pollutant discharge elimination
system permit coverage under ch. 283, Stats., and may be subject to the
regulations promulgated under that chapter.
(b)
Other treatment.
1. 'Best available technology.' If treatment
other than that specified in par. (a) is proposed, the treatment shall, at a
minimum, satisfy all of the following design and operational standards:
a. Treatment shall include preliminary
treatment prior to granular activated carbon adsorption to remove compounds
that may reduce adsorption capacity of granular activated carbon or interfere
with PFAS removal. The preliminary treatment system may include clarifiers, bag
filter units, clay filter units, or other similar treatment.
b. Following preliminary treatment under
subd. 1.a. and prior to granular activated carbon adsorption under subd. 1. c.,
the treatment shall include cloth filtration, ultrafiltration, or filtration of
a finer pore size.
c. Following
filtration under subd. 1. b., the treatment shall include a minimum of 3
granular activated carbon adsorption units in series. Granular activated carbon
adsorption units shall be optimized for PFAS removal. The granular activated
carbon adsorption units shall have a cumulative minimum empty bed contact time
of 30 minutes. The lead granular activated carbon adsorption unit's media shall
be replaced at a frequency that allows for optimal PFAS removal but no less
frequently than once per treatment of each 10,000 bed volumes. Following media
replacement, the lead unit shall be moved to the lag unit position with each of
the other units moved forward one position in the series. The granular
activated carbon media shall be derived from bituminous coal unless the
discharger utilizes a more frequent media replacement schedule appropriate for
that media and receives approval under subd. 2.
d. Treatment shall include at least one
anion-exchange resin polishing unit to remove trace PFAS compounds.
e. Sampling ports shall be provided
immediately after each treatment unit, including between granular activated
carbon adsorption units.
f. If any
sludges or solids are produced during any stages of treatment, they shall be
solidified by mixing with cementitious materials or a comparable process prior
to disposal at a licensed solid waste facility. Sludges or solids generated
during the treatment process may not be disposed of via land
application.
2.
'Alternative treatment technology.' The department may, on a case-by-case
basis, approve an alternative treatment technology to any of the treatment,
design, and operation requirements under subd. 1., if the applicant can
demonstrate that the proposed alternative treatment system will achieve
treatment equivalent to or better than a system specified under subd.1.
Requests for approval of alternative requirements shall be made in writing and
accompanied by written justification including performance data from pilot
installations if requested by the department.
Note: Alternative treatment technologies may
include solutions that improve upon the best available technology, existing
alternative systems such as reverse osmosis with treatment of reject water, or
modifications to the best available technology such as use of 2 granular
activated carbon units with tailored operation and management plans to ensure
prevention of breakthrough, or use of non-bituminous granular activated carbon
media with an appropriately adjusted minimum empty bed contact
time.
3. 'Treatment systems
review.' Construction or modification of any treatment system subject to this
paragraph requires plan review and approval prior to commencement of
construction, in accordance with ch. NR 108 and s.
281.41,
Stats.
4. 'PFAS treatment.' Any
treatment system subject to this paragraph shall be operated to minimize the
level of PFAS substances in effluent, and a person operating a treatment system
shall take actions under this subsection to maintain appropriate and effective
foam treatment. Actions taken under this subsection shall be documented in
writing, and that documentation shall be retained for at least 3 years and made
available to the department upon request.
