(1) SITE-SPECIFIC PROHIBITION IN RESPONSE TO
GROUNDWATER CONTAMINATION WHICH EXCEEDS AN ENFORCEMENT STANDARD. If, at a point
of standards application, the concentration of a pesticide substance in
groundwater attains or exceeds an enforcement standard, and if the
concentration has resulted from or may be affected by a pesticide use, the
department shall, as a site-specific response under s.
ATCP 31.07, prohibit the pesticide use on a site-specific
basis unless the department is shown, and determines to a reasonable certainty
by the greater weight of the credible evidence, that an alternative response
will achieve compliance with the enforcement standard. The scope and duration
of the site-specific prohibition shall be reasonably designed to achieve and
maintain compliance with the enforcement standard at the point of standards
application, and at other downgradient points to which the pesticide substance
may migrate. A prohibition may remain in effect indefinitely unless the
department is shown, and determines, that resumption of the pesticide use is
not likely to cause a renewed or continued violation of the enforcement
standard. The department's responsibility to initiate a site-specific
prohibition under s.
160.25,
Stats., and this subsection is not affected by sub. (2), or by contemporaneous
findings that concentrations of the same pesticide substance at other points of
standards application fall below the enforcement standard.
(2) SITE-SPECIFIC PROHIBITION IN RESPONSE TO
GROUNDWATER CONTAMINATION WHICH EXCEEDS A PREVENTIVE ACTION LIMIT, BUT NOT AN
ENFORCEMENT STANDARD. If, at a point of standards application, the
concentration of a pesticide substance in groundwater attains or exceeds a
preventive action limit but not an enforcement standard, the department may not
implement a site-specific response under s.
ATCP 31.07 prohibiting a pesticide use unless the
department:
(a) Determines, pursuant to s.
160.23(4),
Stats., that no less restrictive response would prevent the violation of an
enforcement standard at the point of standards application.
(b) Establishes the basis for the geographic
scope and duration of the prohibition; and
(c) Limits the scope and duration of the
prohibition to that which is reasonably necessary to maintain compliance with
the enforcement standard at the point of standards application.
(3) STATEWIDE OR REGIONAL
PROHIBITION. The department may, by rule under s.
ATCP 31.09, prohibit a pesticide use on a statewide or
regional basis, as well as on a site-specific response basis, if the department
does all of the following:
(a) Determines
that groundwater contamination has occurred or is likely to occur on a
statewide or regional basis as a result of the pesticide use.
(b) Determines that a statewide or regional
prohibition is necessary to achieve or maintain compliance with an enforcement
standard. In determining the need for a statewide or regional prohibition, the
department shall consider:
1. The extent,
age, reliability, and geographical distribution of groundwater sample test
data; and
2. The extent to which
local conditions and circumstances can reliably be considered characteristic of
a larger region, or of the state as a whole.
(c) Determines that compliance with the
enforcement standard cannot reasonably be achieved and maintained by other,
less restrictive measures.
(d)
Establishes the basis for the scope and duration of the prohibition.
(e) Limits the scope and duration of the
prohibition to that which is reasonably necessary to achieve and maintain
compliance with the enforcement standard.
(4) REPEALING A SITE-SPECIFIC PROHIBITION.
(a) The department may repeal or modify a
site-specific prohibition under sub. (1) if all of the following conditions are
met:
1. Tests on at least 3 consecutive
groundwater samples, drawn from each point of standards application in the
prohibition area at which the concentration of the pesticide substance
previously attained or exceeded the enforcement standard, show that the
concentration of that pesticide substance at that point of standards
application has fallen to and remains at a level which is at or below the level
specified by the department under par. (c). The 3 consecutive samples shall be
collected from each point of standards application at intervals of at least 6
months, with the first sample being collected at least 6 months after the
effective date of the site-specific prohibition. A monitoring well approved by
the department may be substituted for any point of standards application which
is no longer available for testing, provided that the monitoring well qualifies
as a point of standards application under s.
ATCP 31.03.
2.
Tests of groundwater samples drawn from other points of standards application
in the prohibition area during the retesting period under subd. 1., if any,
reveal no other concentrations of the pesticide substance that exceed the level
specified by the department under par. (c).
3. The department determines, based on
credible scientific evidence, that renewed use of the pesticide in that
prohibition area is not likely to cause a renewed violation of the enforcement
standard.
Note: If a site-specific prohibition is created by rule, it
can only be repealed or modified by rule. If a site-specific prohibition is
created by special order under s.
94.71(3) (c), Stats., it can only be repealed or
modified by special order. This subsection establishes conditions which must be
met before the department adopts a rule or issues a special order repealing or
modifying a site-specific prohibition. The subsection does not, by itself,
repeal or modify any site-specific prohibition.
The department plans to continue its program of groundwater
research, and will continue to monitor groundwater in areas where there is
significant potential for repealing or modifying a prohibition. However, the
department is not legally obligated to conduct specific groundwater research or
perform specific groundwater tests at the request of a person who wishes to
have a site-specific prohibition repealed or modified.
The department may accept test results from other sources if
the department considers those test results reliable. Persons who question the
reliability of test results used to maintain, modify or repeal a prohibition
may submit information showing why the test results are unreliable. If the
department finds that there are reasonable grounds to question the reliability
of any test result, the department will attempt to perform additional sampling
and testing to verify the test result.
(b) As a condition to repealing or modifying
a site-specific prohibition under par. (a), the department may do any of the
following:
1. Provide for continued
groundwater monitoring at points of standards application where the
concentration of the pesticide substance previously attained or exceeded the
enforcement standard, or at monitoring wells substituted for those points of
standards application under par. (a) 1. At a minimum, groundwater from those
points of standards application or monitoring wells shall be sampled and tested
during the second and fifth years after the department repeals a site-specific
prohibition.
2. Impose pesticide
use modifications that are reasonably designed to achieve and maintain
compliance with the preventive action limit at all points of standards
application in the prohibition area where concentrations of the pesticide
substance attained or exceeded that limit, and at all downgradient points to
which that pesticide substance may migrate from those points of standards
application. The department may continue to prohibit pesticide use in portions
of the original prohibition area where, because of conditions unique to those
smaller areas, a prohibition is justified under sub. (2).
Note: For example, as a condition to repealing a pesticide
use prohibition, the department may limit pesticide application rates and
methods of application where appropriate, to achieve and maintain compliance
with the preventive action limit. The department may continue to prohibit
pesticide use in portions of the original prohibition area where, because of
conditions unique to those smaller areas (e.g., unique soil types), nothing
short of a prohibition will prevent a renewed violation of the enforcement
standard.
The repeal of a prohibition area does not affect any
responsibility which the department has under s.
ATCP 31.07 to take other appropriate action to minimize the
concentration of the pesticide substance where technically and economically
feasible, and to restore and maintain compliance with the preventive action
limit. The department may also reinstate a repealed prohibition area if
groundwater testing at a point of standards application shows an increasing
trend of pesticide contamination, suggesting that contamination may again
attain or exceed the enforcement standard.
(c) The department shall by rule specify a
level to which concentrations of a pesticide substance must fall before the
department may repeal or modify a site-specific prohibition under par. (a). The
specified level shall be sufficiently below the enforcement standard so that,
when groundwater test results under par. (a) 1. and 2. fall at or below the
specified level, the department can reasonably conclude that groundwater
concentrations in the prohibition area are below and can be expected to remain
below the enforcement standard.
Notes
Wis. Admin. Code Department of Agriculture, Trade and Consumer Protection
ATCP 31.08
Cr. Register, September,
1985, No. 357, eff. 10-1-85; cr. (4), Register, March, 1998, No. 507, eff.
4-1-98.
