The protection and improvement of water quality in Lake Whatcom has been a priority of Whatcom County government for many years. Not only is Lake Whatcom the drinking water source for approximately half of all county residents, it also has many ecological, recreational, and aesthetic values and functions that benefit all citizens. Whatcom County works closely with our Lake Whatcom Management Team partners, the City of Bellingham and the Lake Whatcom Water and Sewer District, to coordinate the many programs designed to protect and improve water quality in the lake. Perhaps the most visible of these programs is the construction of capital facilities to collect and treat stormwater runoff before it enters the lake.
Prior to the implementation of current development regulations, many roads and buildings were constructed without accompanying facilities to capture and treat stormwater runoff. When rain falls on these areas, it picks up contaminants such as nutrients, metals and bacteria and carries these contaminants to the lake. Once in the lake, these contaminants, especially nutrients such as phosphorus, cause problems with dissolved oxygen levels, algae growth and temperature. Whatcom County's capital program in the Lake Whatcom watershed is designed to retrofit areas without stormwater treatment facilities and provide opportunities for contaminants to be removed from stormwater runoff before it reaches the lake.
Since the inception of the stormwater division within the Public Works Department in 2005, Whatcom County has invested approximately $4.8 million of local and state funds in stormwater treatment facilities throughout the watershed at locations such as Cable Street, Lahti Drive, Brownsville Drive, the west reach of Silver Beach Creek, Coronado Avenue and Fremont Street. Typically, these projects include several different technologies or "best management practices" to remove contaminants, depending on the available space and underlying soil types. A common best management practice is an underground vault full of cartridges that filter contaminants out of stormwater. These vaults require annual maintenance to replace the cartridges and maintain their ability to filter out contaminants. Another common practice is a bioinfiltration swale such as the one near the intersection of Lahti Drive and Britton Road. A bioinfiltration swale includes a combination of vegetation, engineered soils and underlying drains to remove contaminants and infiltrate the treated water into the soil. In many cases, the most effective best management practice is to stabilize an eroded stream channel with vegetation, rocks or logs to prevent further erosion, transport of contaminants and sediment during heavy rains.
The effectiveness of the stormwater capital program is dramatic. To date, runoff from over 700 acres in the county portion of the Lake Whatcom watershed is captured and treated before reaching the lake. Phosphorus, one of the most detrimental contaminants in stormwater runoff, is now reduced by over 60 percent in the treated areas. This equates to removal of an estimated 130 pounds of phosphorus from stormwater runoff each year. For a contaminant that is typically measured by micrograms in a liter of water (one microgram per liter equals one pound phosphorus in approximately 120 million gallons of water), 130 pounds of phosphorus removal is significant.
Whatcom County maintenance crews provide other key elements of our program to protect and improve water quality. Whatcom County maintains a program of high-efficiency street sweeping in the Lake Whatcom watershed to prevent sediment and oil from being transported into the lake. Catch basins in the watershed are cleaned out twice per year to remove accumulated sediment. Our crews also maintain the extensive network of ditches in the watershed, which trap many tons of phosphorus-laden sediment every year. By periodically digging these ditches back to their original grade, this trapped sediment and the associated contaminants are removed from the Lake Whatcom watershed. Our crews have developed and refined methods to rapidly revegetate the ditches to restore their water quality function and prevent erosion of exposed soils.
To continue our efforts to protect and improve water quality in Lake Whatcom, Whatcom County has developed an aggressive work plan moving forward to address other areas in the watershed that need stormwater treatment. On Oct. 8 the Whatcom County Council adopted the six-year water resources improvement program, a strategic planning and policy document that outlines surface water capital projects planned in Whatcom County for the years 2014 - 2019. One section of this document relates solely to work planned in the Lake Whatcom watershed. A copy of this document is available on the Whatcom County Public Works website, co.whatcom.wa.us/publicworks/.
One of the most exciting projects contained in the water improvement program is a cooperative joint project with the city of Bellingham planned for construction in 2015. This project, located on the shores of Lake Whatcom near Academy Road, will treat stormwater runoff from 80 acres of developed area and remove an estimated 20 pounds of phosphorus each year. The project will include a pretreatment unit to remove sediment and oil, bioinfiltration swales and underground vaults to provide a high level of treatment. The city has recently acquired the necessary property for construction, and the county is working on design and permitting for the project. Construction is estimated to cost $1.1 million, jointly financed by the city and county, as well as possible state grants. This project illustrates the degree of cooperation that exists between the county and our Lake Whatcom management team partners as we strive toward achieving our common goal of continuing to protect Lake Whatcom.
ABOUT THE AUTHOR
Chris Brueske is Whatcom County's assistant public works director. Contact Brueske at 360-676-6692 or email@example.com. This is one of a series of monthly Civic Agenda reports The Bellingham Herald invited Whatcom County Executive Jack Louws to provide to share updates about Whatcom County issues and projects. He invites citizens to contact him at 360-676-6717 or firstname.lastname@example.org.