Current through September 21, 2024
(a) Ammonia.
(i) The toxicity of ammonia varies with pH
and temperature and the applicable limitations are included in the tables in
Appendix C of these regulations. The numeric ammonia criteria in Appendix C
apply to all Class 1, 2AB, 2A, 2B and 2C waters.
(ii) In all Class 2D and 3 waters,
concentrations of ammonia attributable to or influenced by human activities
shall not be present in concentrations which could result in harmful acute or
chronic effects to aquatic life, or which would not fully support existing and
designated uses.
(b)
Specific numeric standards for a number of toxicants are listed in the "Aquatic
Life Acute Value" and "Aquatic Life Chronic Value" columns in Appendix B of
these regulations. These standards apply to all Class 1, 2 and 3 waters. For
these pollutants, the chronic value (four (4) day average concentration) and
the acute value (one (1) hour average concentration) shall not be exceeded more
than once every three (3) years.
(c) Others. For those pollutants not listed
in Appendix B or C of these regulations, maximum allowable concentrations on
Class 1, 2 and 3 waters shall be determined through the bioassay procedures
outlined in the references listed in Appendix E of these regulations.
(d) In certain waters, the criteria listed in
Appendix B or C of these regulations may not be appropriate due to unique
physical or chemical conditions. In such cases, acute and chronic values may be
determined using the site-specific procedures outlined in the references listed
in Appendix E or other scientifically defensible methods.
(e) Aquatic pesticides specifically designed
to kill, repel or mitigate aquatic pest problems (e.g. mosquito larvae or heavy
plant growth in irrigation ditches) may be added to surface waters of the state
if the use and application is in compliance with the following:
(i) The pesticide used is a product which has
been registered with the EPA and the Wyoming Department of Agriculture for use
in the state, in accordance with
W.S.
35-7-356;
(ii) The application is conducted by a person
licensed by the Wyoming Department of Agriculture to purchase and apply
restricted use pesticides in the state;
(iii) All applications of aquatic pesticides
must be administered in accordance with label directions. However, compliance
with label directions shall not exempt any person or agency from the penalty
provisions of
W.S.
35-11-901 should non-target species or
non-target areas be affected.
(f) This section shall not apply to the use
of fish toxicants if the use and application is in compliance with the
following:
(i) The pesticide used is a product
which has been registered with the EPA and the Wyoming Department of
Agriculture for use in the state, in accordance with W.S.
W.S.
35-7-356;
(ii) The application is conducted by a person
licensed by the Wyoming Department of Agriculture to purchase and apply
restricted use pesticides in the state;
(iii) All applications of fish toxicants must
be administered in accordance with label directions. However, compliance with
label directions shall not exempt any person or agency from the penalty
provisions of
W.S.
35-11-901 should non-target species or
non-target areas be affected.
(iv)
The Wyoming Game and Fish Department may apply fish toxicants to any surface
water of the state provided that prior notice is made to the department and
after receipt of verification from the Water Quality Division that the proposed
application is in compliance with this section.
(v) The National Park Service, as the
wildlife management agency in Yellowstone National Park, may apply fish
toxicants to surface waters within Yellowstone National Park for the purpose of
killing or controlling fish provided that prior notice is made to the
department and after receipt of a verification from the Water Quality Division
that the proposed application is in compliance with this section. Approval from
the Wyoming Game and Fish Department is also required prior to application of
fish toxicants to waters which flow into surface waters of the state outside of
Yellowstone National Park.
(vi)
Private certified pesticide applicators for restricted use pesticides may apply
fish toxicants only to waters located entirely on private property where there
is no surface outlet to waters of the state provided that prior notice is made
to the department and after receipt of verification from the Water Quality
Division that the proposed application is in compliance with this section.
Approval, including any necessary permits, from the Wyoming Game and Fish
Department is also required prior to application of fish toxicants to insure
protection of fish and wildlife resources.
(vii) Pesticide applications must be
conducted in a manner that minimizes to the extent practicable, the magnitude
of any change in the concentration of the parameters affected by the activity
and the length of time during which any change may occur. The application must
include measures that prevent significant risk to public health and ensure that
existing and designated uses of the water are protected and maintained upon the
completion of the activity.
(viii)
Except for the circumstances described in (i) through (vii) above, no other
agency or person may apply fish toxicants in any water of the state.
