Ronald Wastewater District completes Echo Lake Sewer Trunk Line Replacement Project

Echo Lake.  Photo by Dorrena Ortega.

Echo Lake is environmentally safer now that a large capacity, high density polyethylene (HDPE) sanitary sewer pipe has been installed around the west and north sides of the lake by Ronald Wastewater District (RWD).

In anticipation of future growth and higher densities in the south Echo Lake area, and in keeping with the District’s role as an environmental steward, RWD decided in 2010 to increase the carrying capacity and reliability of the aged sanitary sewer lines around the lake. 

The new, larger lines will ensure environmental protection for Echo Lake, provide sanitary sewage carrying capacity for future development and growth, and thereby help to create an economically vibrant community in the Echo Lake area.

CHS Engineers, LLC presented multiple options to increase the carrying capacity of the sanitary sewer lines as part of the pre-design work. Other options included the installation of a new sewage lift station and forcemain or the installation of new sanitary sewer lines on adjacent streets. Variations of these two basic plans were explored. 

The sculpture in Echo Lake Park had to be temporarily moved.

Adding to the complexity of the project was the fact that the Echo Cove Condominiums were built over portions of the sanitary sewer line. These portions of line were sliplined, thereby significantly extending the lines’ useful lives. In addition, a new 18 inch diameter sanitary sewer line was installed around the Echo Cove Condominiums. Because of the excessive depth of parts of this line, ductile iron pipe was installed in addition to polyvinylchloride (PVC) pipe which is normally used. The least expensive option to replace the remainder of the existing Echo Lake Trunk line was to pipeburst and replace it with HDPE 18 inch pipe.

In the summer of 2010, Buno Construction was awarded a contract to replace the 14 inch diameter asbestos-cement sanitary sewer line around Echo Lake. Buno’s total bid price plus change requests was $902,450. Buno Construction was also the low bidder on the Echo Cove Bypass Line at $490,800. The developer of the new apartments and YMCA at the south end of Echo Lake increased the size of the sanitary sewer lines on their site as part of their project.

The Echo Cove Bypass project was completed in January 2011 at a final cost of approximately $380,300 – $110,500 under bid. This was the result of the engineering work by CHS Engineers, LLC and expert construction by Buno Construction.

"In fact," says District Manager Michael U. Derrick, "the Echo Cove Bypass project has been submitted to the Seattle Section of the American Society of Civil Engineers as a '2010-22 Local Outstanding Civil Engineering Achievement Award' candidate."

The Echo Lake Trunk Replacement project was recently completed at a cost of $817,117 – $85,333 below bid amounts. Thoughtful engineering from the start of the project, precise and efficient construction during the project, and a sharp eye for potential savings by both the engineer and contractor produced an excellent sanitary sewer line project along with remarkable savings.

"The Board of Commissioners is proud of the success of this project. Good cooperation and communication between the District, its consulting engineer, and contractor resulted in a success for the ratepayers of RWD. For 60 years, Ronald Wastewater District has been your partner in environmental stewardship. With your support, we’ll continue to provide you with the best sanitary sewer service possible, now and into the future."

--Ronald Wastewater District