Sean C. Morgan
Of The New Era
Sweet Home’s new water treatment plant is beginning to take shape at its new location off 47th Avenue.
Pacific Excavation has completed construction of the clear well below a slab of concrete, the walls and roof of the new structure. Last week, the contractor finished installing the plant’s three filter systems, each of which will provide up to 2 million gallons of drinking water per day to Sweet Home. Pacific also was busy installing three pumps in a new pump house to feed those filters.
Construction began on June 4. So far, Pacific has completed the pump house, connecting it to the raw water line, which draws water from Foster Lake through a connection in the dam. Lines from the pump house to the plant are installed. Water is pumped uphill to the filters inside the new plant structure and then to the clear well below, where the water travels a serpentine route through the well to the water distribution system, providing chlorine contact time that meets drinking water standards.
Another basin outside of the building is complete. It will catch “backwash,” Public Works Director Mike Adams said. That is water used to clean the system. The water goes into the city’s wastewater system, and crews can scoop out the silt and dispose of it.
The clear well and slab extend past the east end of the building to allow for expansion later as needed, Adams said. An expansion would require the expansion of the building, construction of two more filter units and the addition of two pumps in the pump house, allowing the plant to produce up to 10 million gallons per day.
Sweet Home currently uses around 1 million gallons of water per day, a little less during the winter and up to 2 million per day during the summer.
The new plant is located off 47th Avenue west of the old Clear Lumber administrative offices, to the northwest of the Oregon Department of Forestry headquarters at the intersection of 47th and Main streets.
The property includes five acres provided by Santiam River Development Company in exchange for the use of the city’s unused water rights. The city has more than 8 million gallons per day in water rights. Santiam will use the water to fill water features within a proposed development along the north side of Sweet Home, from the plant to Clark Mill Road. As the city grows and demands more of the water, Santiam will use less of the raw water and begin using treated wastewater.
Between the old Clear Lumber building and the new plant are three terraces made from fill from the plant. Those terraces are part of a proposed residential development. When and if constructed, they will be the first water service connections outside the plant. According to current plans, the old Clear Lumber building will be the first.
Allowing the developer to use the fill minimized the city’s costs getting rid of it.
The project remains on schedule and should be complete and on line by the end of July, Adams said.
The city is building the new plant because the existing plant, located at the north end of Ninth Avenue, is incapable of meeting chlorine contact time standards. The standard changed in 1997, requiring water utilities to increase the amount of time chlorine is in contact with water.
Since then, the city has mailed quarterly notices to customers explaining that the water does not meet drinking water standards.
The existing plant was built in the late 1930s with upgrades in the 1960s, and it is deteriorating structurally, according to city officials.