Projects

Project 1: Evergreen Stream Restoration

The full restoration of the Evergreen reach of Bear Creek is a multi-year project that will require extensive cooperation from local business and agencies. The preliminary BCWF estimate of restoration along this reach exceeds 1.25 million dollars. The BCWF proposes doing a phased pro-gram. The first phase will target a section of Bear Creek adjacent to the central parking area. This section of Bear Creek has shown over the last 10-years elevated amounts of asphalt in the sediments and in winter snow conditions, the creek receives most of the snow plowed from the parking lot. The Association data record suggests this snow removal procedure of pushing snow into the creek, which is common through the downtown Evergreen area, is a source of water quality and fishery degradation. The Association believes a redesigned parking lot edge feature along Bear Creek could become an affordable green infrastructure best management practice to reduce pollutant loading from the paved surfaces in the community.

Project 2: Coyote Gulch EutroSORB Pilot

There is an opportunity by the Association to conduct a pilot program on Coyote Gulch that could augment the wetland TP reduction. The Association has reviewed a pilot nutrient reduction system with the company EutroPHIXTM. They have developed a nutrient filtration technology called EutroSORBTM. The EutroSORBTM filtration bags contain a phosphorus absorption material that removes TP from the flow stream as the water flows through and over the bags. The pilot project would securely place specialized large bags of the EutroSORBTM below each of the seven rock drop structures in the plunge pools. The filtration system would remove the free reactive phosphorus from the water and rapidly form it into a highly stable insoluble mineral within the filtration bags. It is estimated that this pilot project would remove about 30 additional pounds of TP (about 1/2 of the current annual load) from reaching the reservoir. The pilot project will be operated for 1-year. The actual TP removal will be monitored using the existing Association monitoring plan and assessed seasonally.

Project 3: Turtle Ponds PhosLock Pilot

Phoslock is a patented phosphorus locking technology containing lanthanum (5%), a naturally occurring earth element, embedded inside a clay matrix (~95%). Phoslock has the capacity to bind phosphate when applied to aquatic environments and results in a non-toxic mineral that becomes an inert component of the sediments. For over ten years, Phoslock has been successfully used in water resource restoration programs around the world to remove free reactive phosphorus and restore water quality. Although Phoslock is a new technology to the United States (2010), it is rapidly emerging as an effective phosphorus inactivation and water quality restoration solution for ponds, lakes and reservoirs. Before a Phoslock project can be initiated on BCR, it needs to be tested under similar conditions as a pilot project. The BCWA proposes to apply a Phoslock treatment on the Turtle Pond in Bear Creel Lake Park as a short-term pilot project. The 2-acre Turtle Pond is adjacent to Turkey Creek and receives seepage from the creek, but is a contained system. The BCWA would conduct 3-4 month pilot project. The BCWA would monitor pond quality including sediment analysis prior to application with a 6 month follow up analysis of quality changes.

Project 4: BCR Phased PhosLock Project

Phoslock comes in a granular formation that easily goes into a slurry using application equipment with agitation moving high volumes of water. The Phoslock slurry is spread across the application area of a waterbody from a boat or barge by spraying the slurry across the surface or injecting into the water column. Following a likely slurry application of Phoslock to the surface waters of BCR, the lanthanum ions sorbed to the clay matrix will react preferentially with free phosphate compounds in water (removing free reactive phosphorus) and rapidly form a highly stable insoluble mineral on the reservoir bottom. The resulting min-eral complex becomes integrated as an inert component into the sediments of BCR and is not bio-available. Due to the specificity of Phoslock to phosphate, as long as binding sites are available, it will continually bind new incoming phosphorus from internal and external sources. A series of low-dose Phoslock applications can be made over the course of the summer (June-August) to help re-duce in-water phosphorus concentrations at the surface as well as hypolimnetic (deep water) phosphorus levels that are a major contributor to the annual phosphorus load. A phased low dose application process is recommended as part of an adaptive management program. The phase 1 will target the deeper areas of the reservoir (12 acres) around the BCWA buoy (Center of deep portion) with a heavy dose. A second phased low dose program will include a larger portion of the reservoir (80 acres). Ongoing water column monitoring will be used to adjust dosing and frequency (e.g., 2-years).

Project 5: Rooney Gulch EutroSORB

The BCWA will conduct a pilot study on lower Rooney Gulch within Bear Creek Park to reduce phosphorus loading. The BCWA will use EutroSORB (a phosphorus filtration system) to reduce phosphorus loading. EutroSORB filters are a effi-cient and economical solution designed for intercepting free re-active phosphorus (SRP) from moving water. The EutroSORB reactive filter media is contained in mesh bags that is secured within the flow channel and left for a specified period of time. The filter media is safe to aquatic life, does not dissolve, and is removed from the environment when the filter has met capacity. The BCWA will secure about 24 twenty –five pound mesh bags (total of about 600 pounds of EutroSORB filter media in the drainage channel below the culvert. The pilot project will run for about 6 months (May through October).

Project 6: Coyote Crossing EutroSORB

The BCWA will conduct a pilot study on lower Coyote Crossing within Bear Creek Park to reduce phosphorus loading. The BCWA will use EutroSORB (a phosphorus filtration system) to reduce phosphorus loading. EutroSORB filters are a efficient and economical solution designed for intercepting free reactive phosphorus (SRP) from moving water. The EutroSORB reactive filter media is contained in mesh bags that is secured within the flow channel and left for a specified period of time. The filter media is safe to aquatic life, does not dissolve, and is removed from the environment when the filter has met capacity. The BCWA and BCWF will secure about 20 twenty –five pound mesh bags (total of about 500 pounds of EutroSORB filter media in the lower drainage channel above the bridge crossing culvert. The pilot project will run for about 8 months (May through December).

Project 7: Horseshoe Pond Lakewood EutroSORB

The BCWF and Lakewood will conduct a pilot study in the stormwater inflow water to Horseshoe Pond to reduce phosphorus loading and potentially reduce summer bluegreen blooms. The BCWF and Lakewood will use EutroSORB (a phosphorus fil-tration system) to reduce phosphorus loading. EutroSORB filters are an efficient and economical solution designed for intercepting free reactive phosphorus (SRP) from moving water. The EutroSORB reactive filter media is contained in mesh bags that is secured within the flow channel and left for a specified period of time. The filter media is safe to aquatic life, does not dissolve, and is removed from the environment when the filter has met capacity. The BCWF and Lakewood will use a single application ap-proach to reduce phosphorus loading. The pilot project will secure 72 twenty–five pound mesh bags (total of 1,800 pounds of EutroSORB filer media in the inlet chan-nel). The channel width of 3-4 feet will require two bags at each P1 site. The placement of the 25-pound filter media bags will minimize any erosion potential. Data collection will be done over 6+ months using a two point monitoring site process in the channel (HSP 100a and HSP 100b), with an additional sampling location within Horseshoe Pond. The pilot project will run from July through January). Most of the bags will be removed in January 2022, several bags maybe left in the field to test how they endure winter conditions.

Project 8: Wilmont Drainage EutroSORB

The BCWA and Evergreen Metro District will conduct a pilot study in the in-flow water from Wilmont drainage to reduce phosphorus loading into Evergreen Lake. The BCWA will use EutroSORB (a phosphorus filtration system) to reduce phosphorus loading. EutroSORB filters are an efficient and economical solution designed for intercepting free reactive phosphorus (SRP) from moving water. The EutroSORB reactive filter media is contained in mesh bags that is secured within the flow channel and left for a specified period of time. The filter media is safe to aquatic life, does not dissolve, and is removed from the environment when the filter has met capacity. The BCWA will use a single application approach to reduce phosphorus loading. The pilot project will secure 88 twenty–five pound mesh bags (total of 2,200 pounds of EutroSORB filter media) in the Wilmot drainage channel adjacent to the City and County of Denver golf course. The placement of the 25-pound filter media bags will minimize any erosion potential. Water quality data collection will be done over 5+ months using a two point monitoring site process in the channel (above and below the project). The pilot project will run from July through December 2021. Most of the bags will be removed in 2021, several bags maybe left in the field to test how they endure winter conditions.