Cottage Grove is getting a facelift at its I-5 entrance.
Last week, hundreds of Goldsturm Black-Eyed Susans were been planted in the northwest portion of the interchange, with many other flowering and shrub varieties on their way.
Around 12,000 shrubs and ground cover in total are planned for the interchange. Grassy areas will also be fortified with new grass seed.
“The city will have a green interchange throughout the year that reduces fire danger during the dry season. And it will be an interchange that citizens can be proud of,” said Cottage Grove Civil Engineer Ryan Sisson.
The project is also part of a larger irrigation system upgrade which will discharge recycled wastewater, or effluent, onto grassy and vegetated areas.
Middlefield Golf Course, owned by the city, has until now been the only site used for such irrigation.
At times, there has been more treated effluent than places to disperse it.
The city’s effluent, which has been treated to remove contaminants, is discharged either by way of irrigation or released into the Coast Fork of the Willamette River.
With limited options, the city has run afoul of a few Department of Environmental Quality (DEQ) violations over the years, but it is hoped the extra 15 acres for irrigation at the interchange will help mitigate these issues.
“DEQ’s requirements became more stringent, so therefore, we needed more area and the golf course was just getting too wet, even during dry summers,” said Sisson. “So [the interchange] provides more capacity and more area for us to discharge the recycled water as part of a plan to distribute recycled water to not only the interchange, but to Bohemia Park.”
Within the next couple years, there are plans to construct an eight-inch main that will bring recycled water from the wastewater plant down Douglas Avenue toward Bohemia Park and the Row River Trailhead Park.
City staff have routinely expressed confidence in the level of safety in the city’s effluent, placing it just one level below typical drinking water.
“You could factually say it’s Class A wastewater. It’s the highest level of wastewater — it’s cleaner than the river,” said Sisson. “The problem is that it’s warmer than the river during the summer. It adds gradients of temperature to it that accumulate with every community’s addition of wastewater to it. And by the time you get to Portland, it’s non-viable for fish.”
The irrigation project, along with a 12-million gallon storage pond, will be a long-term solution to relieve the city of trying to find places to discharge the recycled water.
Irrigation for the interchange is in its final stages and the contractor, Milfroy Golf Systems, is expected to be completed by mid-November.