Netarts Oceanside Sanitary District (NOSD) – WWTP Improvements

The Netarts Oceanside Sanitary District (NOSD) was faced with an aged and out-of-date wastewater treatment plant that was more than 30 years old and had no room for expansion. In addition to the aged and outdated wastewater treatment plant, NOSD had an agreement order with the Oregon DEQ to improve the wastewater treatment plant. NOSD looked for a new site, as their site was not suitable for expansion. Steep terrain and high property values posed a problem when looking for property adjacent to the existing site. In addition, there was no property available that was large enough or geologically stable within the district. NOSD identified a potential site nearby but it was both outside the district boundaries and zoned for timber production. NOSD had to go through a complex land use process and a statewide goal exception was eventually granted. NOSD acquired the land use approval and requisite easements, then had to pass a general obligation bond in order to fund the project.

This project was complex and much greater than simply a wastewater treatment plant and involved several major components:

1. A new main pump station at the existing site with pumping equipment designed to provide 450 feet of total dynamic head.

2. Electrical, phone conduit to and from the WWTP that were 7,000 LF each.

3. 7,000 LF of 16-inch HDPE, and 7,000 LF of 20-inch HDPE.

4. 4,600 LF access roadway to the new plant.

5. A potable water line to the new treatment plant.

6. The wastewater treatment plant included a new headworks, a three-basin sequencing batch reactor, UV disinfection, two sludge storage lagoons, and associated structures that included a shop building, administration building, and a blower building.

7. Reconstruction of the Oceanside pump station.

8. Demolition of the original wastewater treatment plant.

This project had many challenges including the following:

1. Constrained space at the site.

2. Sequencing of the project had to keep the existing facilities operational. At one point NOSD had to move out of their administration building in order for construction to begin and then move back into the new administration building while construction continued.

3. There were several environmental and cultural issues at this site. Extensive archaeological work was done including the discovery of shell middens from former Native American camps along both the pipeline routes at the Oceanside pump station.

4. There was limited access to the site during construction of the project as a landslide closed the state highway adjacent to the site for several months. NOSD had to negotiate a deal with the timber companies in order to gain access to the site during this time.

5. Exposed headland conditions subjected the project to extreme weather including months with over 20-inches of rain and winds in excess of 100 mph.

6. Funding for the project was limited by a small community so the funding package took a significant amount of work to assemble and ultimately included a combination of local money plus loans and grants through the U.S. Department of Agriculture Rural Development program.

The Netarts Oceanside Sanitary District Wastewater Treatment Plant Improvements Project was completed in February of 2013, and has produced effluent complying with all the permit requirements from the first day it was placed into service. Effluent quality has continually run well below permit limits.

The treatment plant and facilities are designed to accommodate growth with the community over the next twenty years, and the new site also has room to expand in the future should the need arise.

All work was accomplished through a team effort, was a success from the start and has resulted in an improved facility for the Netarts-Oceanside community that will serve the community for many years to come.

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Owner: Netarts Oceanside Sanitary District (NOSD)

Engineer: Westech Engineering

Location: Netarts, Oregon

Completion Date: 2013