Cooling water discharges are subject to default federal or state-wide temperature standards. Normally, a facility with cooling water discharges could meet the temperature standards if it can demonstrate that the discharge temperatures would be below the default standards after mixing with a receiving water such as a stream, river, or lake. This was not possible for this food manufacturing facility in the Midwest since its associated discharges are the only source to the receiving water, and therefore mixing with the receiving waters is not possible. As such, the facility obtained a Clean Water Act (CWA) Section 316(a) Variance from the state-wide default standards. The CWA Section 316(a) variance process allowed the facility to re-derive new temperature standards by demonstrating that the re-derived standards still assures the protection of the natural habitat and the aquatic organisms living in those waters.
Since the approval of the facility’s CWA Section 316(a) Variance, the Midwest state has updated the guidance with strict requirements that have to be met for renewal of the variance. These requirements include complex and expensive in-field studies. In addition to the costs, the results of the in-field studies are open to interpretation, and therefore renewal of the variance may be in jeopardy. Without approval of a renewed variance, the facility would be forced to close.
Given the complexity and significant costs of the required in-field studies, in addition to the unknown interpretation of the results, the decision was made to propose renewal of the variance without the field studies. To make this proposal, the facility provided updated information that confirmed that the:
- Discharges were similar in flow and temperatures to what was assumed for the original variance approval; and,
- Natural habitat and the aquatic organisms living in the receiving waters are still protected.
The renewal application has been submitted for review. It is anticipated that the application will result in renewal of the variance without the need for field studies.