The Montana Department of Environmental Quality (DEQ) is now accepting public comment on its draft programmatic Environmental Assessment (EA) for the construction and operation of subsurface wastewater treatment systems (SWTS).
A coalition of conservation groups, including Upper Missouri Waterkeeper, Montana Environmental Information Center, and Clark Fork Coalition, is urging DEQ to withdraw this proposal and strengthen rules for SWTS to prevent the negative impacts this polluting sector has proven to have on water resources.
Why This Matters
Domestic wastewater discharges and their infrastructure are a significant source of pollution contributing to the degradation of Montana’s water resources. DEQ has consistently failed to address the threat posed by wastewater pollution, including the negative cumulative impacts caused and contributed by sprawl residential wastewater discharges.
As residential development continues to grow, so too do the cumulative impacts of septic systems on our groundwater, rivers, and streams. Montana’s waterways are uniquely sensitive to chronic nutrient pollution, yet DEQ’s proposed EA ignores the need for stronger protections for SWTS and instead seeks to create an expedited framework for processing residential development applications without meaningful or site-specific environmental reviews.
Key Issues with the Draft EA:
- Streamlining over scrutiny – The Draft EA includes a “Categorical Exclusion Checklist” that fails to evaluate environmental impacts of individual SWTS and the cumulative water resource impacts of SWTS.
- Misleading reliance on engineering standards – Compliance with engineering standards is treated as proof of no environmental harm, despite evidence that these systems still contribute nutrients, bacteria, and viruses to waterways.
- Ignoring cumulative impacts – The Draft EA assumes impacts from SWTS are nonsignificant in most cases, without defining thresholds or requiring analysis of combined pollution from multiple systems.
- Reduced public participation – The Draft EA would limit opportunities for public participation and transparency in decision-making.
- Conflicts with existing water quality realities – Over 30% of assessed Montana waters are already impaired, and SWTS are widely recognized, including in DEQ’s own analyses, as a leading source of nutrient pollution. Yet, the EA does not prohibit new systems in already impaired watersheds or require consideration of existing Total Maximum Daily Loads (TMDLs).
- Undermining Montana’s constitutional guarantees – Montana’s Constitution guarantees the right to a clean and healthful environment, and affirmative, preventative and anticipatory decision-making by DEQ. This Draft EA reverses the burden of proof and assumes minimal harm unless proven otherwise, rather than requiring proactive protection for our state’s waterways.
What Needs to Happen
We’re calling on DEQ to withdraw the Draft EA as proposed, and instead, revise and strengthen regulations for SWTS and land use controls for residential development to prevent the proven, negative cumulative impacts from SWTS on Montana’s waterways.
Take Action
DEQ is accepting public comment on the Draft EA until May 1, 2026. Submit comments here.