By Kristin Gardner and Karen Filipovich EBS CONTRIBUTORS
Turn on the shower, order
a meal or flush the toilet. All of these activities involve water going down
the drain. In Big Sky, what happens next and the resulting quality of treated
water varies significantly depending on the type of wastewater treatment
system.
Wastewater treatment
infrastructure varies in the Big Sky area from single septic systems to large,
centralized systems. Wastewater treatment removes solids, pathogens and
nutrients. Doing so protects human health and safeguards water supply and water
quality.
Septic systems are
designed for small, individual sites in areas with low density development.
They are commonly found in the more remote areas of Big Sky, like the Gallatin
Canyon or Beaver Creek. With this system, a tank settles out solids and
bacteria digest nutrients and pathogens and the resulting effluent is then
usually released into a drainfield.
There are two major types
of septic systems: Level 1 and Level 2. Level 1 systems are more common and
easier to operate, but do not remove as many nutrients as other methods.
Typically, this system treats effluent to a point where total nitrogen
concentration is about 50 milligrams per liter. Level 2 systems treat to a
higher level, and are required to remove total nitrogen to a concentration of
less than 24 milligrams per liter.
Level 2 systems are
significantly more expensive than Level 1 systems and are more difficult to
operate. However, these treatment levels are only achieved if a system is
properly maintained. The individual landowner has complete responsibility of
the system including any maintenance and testing.
Public wastewater
treatment systems vary greatly in size and treatment methods around Big Sky,
ranging from systems servicing a single business, to large groups of
residential and commercial development. In Big Sky, these systems range from
large onsite systems that are similar to individual septic tanks but serve
multiple households or businesses, to treatment lagoons and multistep technologies.
Treatment levels vary greatly based on technology, but all public systems
require routine monitoring and reporting to the state.
The largest public wastewater treatment plant in
the area is the Big Sky Water and Sewer District, which services the Meadow and Town Center areas, the Big Sky Resort base area, and parts of Spanish Peaks. The district’s facility is a tertiary treatment plant and achieves treatment levels similar
to most of the smaller community treatment
systems in Montana. The
treated effluent’s total nitrogen ranges from 4 to 35 milligrams per liter depending on the time of year. The
district is in the process of designing an
upgrade and expansion that
would achieve nitrogen
concentrations of less than 5 milligrams
per liter, similar to the Bozeman wastewater treatment plant and compliant with Montana’s Class A-1 reuse standards,
the highest quality described by the Montana Department of Environmental Quality.
Improving wastewater
treatment levels is very important as Big Sky grows because more effluent will
be generated as more people move in and visit the area. Higher treatment levels
also allow for more diverse reuse options for the treated water, which could be
greatly beneficial to watershed health.
Kristin
Gardner is executive director of the Gallatin River Task Force. Karen
Filipovich is a facilitator and consultant in the Bozeman area.
—
ADDITIONAL RESOURCES:
Wastewater treatment in the
Gallatin Canyon:
Gallatin Canyon Project
Kickoff Meeting
Sept. 19 at 6:30 p.m.
Buck’s T-4
Canyon
residents and business owners are invited to learn more aboutan
engineering study that will provide information about wastewater treatment
upgrade options in the Gallatin Canyon. This study is administered by the
Gallatin River Task Force and funded through the Big Sky Resort Tax. Contact Karen Filipovich at
karen.filipovich@gmail.com or kristin@gallatinrivertaskforce.org for more information.
Big Sky Water and Sewer District wastewater
reclamation upgrades:
Big Sky Water and Sewer District – bigskywatersewer.com
Septic permitting and maintenance:
Gallatin Health Department – healthygallatin.org/environmental-health/water-quality/wastewater-septic-treatment
Madison Health Department – madisoncountymt.gov/247/Septic-System-Information
Gallatin Local Water Quality District – glwqd.org/septic-wastewater-treatment-systems