Who Needs This Permit?
At the time of this writing, the Wisconsin DNR is requiring certain Wisconsin maple producers to apply for a free Low Impact Discharge Permit if they meet both of the following criteria:
- Using a Reverse Osmosis System
- Meets criteria for DATCP Food Processing License
Since every state is different and laws can change from year to year, we encourage maple producers outside of Wisconsin to contact their local DNR or state maple association for the most up to date information for their state regarding permits. The links in this article are specific to Wisconsin.
What’s the Purpose of This Permit?
The DNR is concerned with the amount of RO water and wastewater (reject water from the wash/rinse process) released to groundwater or to surface water that may carry oil, grease, unhealthy pH and chlorine levels that could harm Wisconsin’s water source and the ecosystems it supports. Permit Fact Sheet
Is RO Water a Pollutant?
Maple Syrup producers fall into the “Low-Impact Discharge” category which acknowledges that RO water is relatively pollutant-free and has minimal impact to water quality of surface water, wetlands or groundwater when managed properly.
Clean RO water — without any chemicals — may be discharged into ground water, so long as its volume does not create erosion. Alternatively, you may be able to sell pure RO water to a beverage company such as Asarasi.
Where you might run into problems is if you are discharging clean RO water to a swamp, creek, river, lake, etc. This may be a pollutant. And RO rinse water which contains chemicals is considered a pollutant.
How do I Apply for a Permit?
Complete an application with the DNR at least 30 days before discharge. Visit the DNR Permits web page and select “Low-Impact Discharge” to get started with the paperwork. Permits must be renewed every five years.