June 6, 2005—About January 2004 the city received the plans for the new wastewater treatment plant from Carollo Engineering. The city engineers then reviewed the plan in great detail, tracing every pipe and wire to insure that the plan would meet their needs. Fifteen federal, state, and county agencies were involved in approving the plans and issuing the needed permits. Since a majority of Gray's Ranch is classified as wetlands, the CA Dept. of Fish and Game (CA DFG) has jurisdiction over the property and has required that the plant be split into two sections, preserving existing seasonal wetlands. The state declared the old farmhouse a historic building which required preservation plans. More modifications were made to satisfy the requirements of other agencies. After all these issues were resolved, the Water Resources Department staff (3-4 people) prepared huge stacks of documents for the city council's approval, then shipped the approved documents to the various contractors interested in bidding on the construction, which is expected to exceed $100 million. The bidding closes in mid-July, and it is hopeful that the city council will quickly approve one of the bidders so that construction can begin in September.
Time has become a critical factor on this project for two reasons: our present plant is 70 years old and failing, which has generated pressures from the state for replacement, and construction costs are increasing at the annual rate of 15%, due to international competition for steel and concrete. The sooner the project is started, the lower its final cost. The construction will take about three years to complete.
PWA will continue to work with the city to help make this water treatment plant also function as a quality wildlife sanctuary, with public access, as was done at the Arcata Marsh & Wildlife Sanctuary. PWA has made trips to Arcata to discuss these various issues with the creators of the Arcata project and will share the creators' suggestions with the city. PWA is also available to help the city with invasive weed removal issues and habitat creation in the wetlands. PWA is also building a quality docent program to meet the needs of this new wetlands site. Because of their jurisdiction over the wetlands, CA DFG will continue to play an active roll at Gray's Ranch.
THE DESIGN OF THE NEW PETALUMA WASTEWATER TREATMENT PLANT
7/04, updated 6/05—After several years of design modifications, the city has decided to build their new wastewater treatment plant on about 25 acres in the upper portion of the 270-acre Gray's Ranch, which the city purchased in early 2004 (see illustration below). The primary and secondary treatment modules will include two elliptical oxidation ditches, biofilters, and two clarifiers. The site will also include the laboratory, tertiary filtration filters, disinfection units, and other hardware associated with the operation. Connected to the plant will be 45 acres of polishing wetlands, divided into four ponds.
About 230 acres of the site will be open to the public with walking trails, educational areas, public parking, and access to the natural brackish tidal marsh which occupies the lower third of the property. There will be a connecting trail to Shollenberger Park. The old oxidation ponds, located on the adjacent property (to the south), will be renovated with ponds nine and ten converted to densely vegetated treatment wetlands.
In March 2005 the Petaluma City Council voted to send the project out for bids. The bids are due back to the city on 14 July 2005, the contract awarded 1 August 2005, and construction likely to begin September/October 2005. The project is estimated to be finished in late 2008. The public access to the freshwater polishing wetlands and the natural tidal wetlands will provide a wonderful venue for enjoying wildlife and participating in the many wetlands/watershed educational programs being planned for the site. Money to create some of the public amenities on the site is lacking but will be sought along the way. Thus some features, such as an education center, may appear after the project finishes in 2008.
OCTOBER 2007 UPDATE ON THE WASTEWATER TREATMENT PLANT
Construction on the new wastewater treatment plant started in October 2005. There are seventeen federal, state, and county agencies monitoring various aspects of the project. After preparing the site for construction, miles of pipes and electrical lines were buried in the ground. After laying the underground pipes, construction of the two oxidation ditches and their supporting clarifiers began. These are immense structures that used large quantities of steel and concrete. Construction of the administration building started shortly thereafter. Construction has remained on schedule and should be complete in the fall of 2008. Then there will be several months of testing before the project opens to the public in the spring of 2009. There will be four polishing wetlands holding a total of about 30 acres of water, plus three miles of trails including a link to Shollenberger Park. A public bathroom and a parking lot for 60 cars and several busses will also be included. The entrance will be from Cypress Drive. The PWA is exploring the concept of creating an interpretation center on the site. Any such center would be built completely with grant money obtained by PWA and staffed by volunteers. The old farm house has been declared a state historical building and could not be removed. It is now boarded up and awaiting restoration by some nonprofit or private group with deep pockets.
The aerial photo of the construction site, taken in August 2007, was made looking north to south. Lakeville Rd is at the bottom of the photo and the Petaluma River (at high tide) at the top. Note the outline of the four polishing wetlands mid-picture and the flooded brackish-tidal wetland beyond the construction area. Many of the roads in the photo (used for construction) will disappear, as will the construction staging areas. The land used for these activities will be restored in 2008 to native seasonal wetlands or uplands.
