Wastewater Management Facility

About the Facility 

The McKinleyville Wastewater Management Facilities are located on a 68.4 acre parcel, with approximately 34 acres presently being used for the treatment facilities, an 18 acre wooded buffer, and 16 acre open parcel to the south. In addition, there is a public access nature trail contained within the wooded buffer zone that is 1.5 miles long.

The wastewater management facilities consist of two primary oxidation ponds (11.2 acres), two secondary oxidation ponds (5.5 acres), two finishing treatment marshes (5.6 acres), and has a total pond area of 22.3 acres. Biological treatment capacity of the ponds is 1.18 mgd (1,180,000 gallons per day) and hydraulic capacity of disinfection facilities (chlorine contact chamber) is estimated at 3.3 mgd (2300 gpm) peak flow.

Treated wastewater is discharged to the Mad River during winter months when the river flow rate surpasses 200 cfs (cubic feet per second). During summer months (May 15 through September 30) and low flow periods of the Mad River, treated wastewater is discharged into two percolation ponds located adjacent to the river and is irrigated on dairy pastures in southwest McKinleyville. The irrigated areas include 70 acres of the Fischer Irrigation Site (at the corner of Fischer Road and School Road) and 28 acres at Hiller Park (east of the Wastewater Management Facility and north of the Hiller Sports Complex).

   The Lawn Mowers

Wastewater Treatment Plant Upgrade

The District completed a 20 Year Wastewater Facilities Plan in January 2012.  The Wastewater Facilities Plan identified a series of upgrades to the District’s existing wastewater treatment plant including portions of the effluent disposal system. 

The improvements will address the needs for the facility through the year 2030.

The District's Wastewater Facilities Plan (Facilities Plan) finalized in January 2012, presented several treatment alternatives and recommended replacing the existing facultative lagoon system with an in-basin extended aeration system. Subsequently, two manufacturers of in-basin extended aeration systems, Bioworks and Parkson, have been chosen as the preferred vendors for the extended aeration system.

The major proposed WWMF improvements include a new headworks facility; aeration basins; a blower/electrical/maintenance building; two new secondary clarifiers, including return activated sludge/waste activated sludge (RAS/WAS) pumping; and a biosolids storage basin.

The preliminary design cost estimate indicates the bid price to be approximately $13.2M.

Biosolids Project (Update 1/9/15)

The first phase of the upgrade progress has just been completed.  Pond 1A was taken out of service, partially drained, and dredged by SynaGro WWT Inc.  The sludge was then dewatered and the resulting biosolids hauled off, prior to breaking ground on the plant upgrade.

This is the pond to be filled for construction of the improvement project.  Upon completion of the biosolids removal, pond dewatering can be accomplished by district staff while still meeting permit requirements on the existing treatment facilities a cost savings to the District.

(Pond 1A, the site of the future construction, has now been 98% dewatered)

Potholing of Existing Facilities (Update 10/31/14)

District staff is in the process of potholing existing facilities.  Potholing is the digging of small holes over pipelines and conduits, so the depth and type of material can be verified. Potholing these facilities allows the contractor to accurately map, and shoot elevations on them, prior to the project commencing.  Having district staff perform this task instead of the contractor is another cost savings to the District.

(Potholing, and shooting of facilities, have been completed)

90% Design (Update 11/21/14)

The 90% design plans for the new plant are expected to arrive from the engineer by November 14th, 2014.  They will be reviewed by District staff and returned to the engineer with further comments.  The design has been accomplished in phases, (30%, 50%, 90% and final) with a comment period by staff after each phase.

(The 90% design plans were reviewed by District staff and comments on them sent to the engineer for consideration.  A review of the Construction Management scope of work was also done by District staff.)

Time Lapse Camera (Update 1/9/15)

A time-lapse camera was recently installed at the plant.  It will take snapshots daily to chronicle the progress of construction.  Following completion of the new upgrade, a video will be made from the snapshots

Wastewater Management Facility Improvement Project Open House (Update 2/5/15)

On December 9, 2014 staff hosted an Open House at Azalea Hall to inform the public and answer questions regarding the Wastewater Management Facility Improvement Project. The Project manager from Kennedy/Jenks was present along with Planwest Partners, Inc. to assist with any questions from the public.

Six exhibit stations were set up to view the process, from the proposed design to the estimated costs and schedule. Approximately 14 members of the public attended, each with questions and comments. There were questions ranging from how their view of the site will be affected to how the proposed process performed and how many years the treatment process would satisfy the NPDES permit. There were concerns on whether or not the District would need to extend the fence boundaries, the increased power consumption and if there will be an increase in odor. There was a lot of positive feedback and the public appeared satisfied with the direction that the District was going with the upgrade.

Final Draft "Bid Set" (Update 3/13/15)

The final draft "Bid Set" plans have arrived and are currently being reviewed by District Staff.  This is the final step prior to going to bid.

(Update 3/27/15)

Comments on the final draft are being prepared by District staff and will be returned to engineers when completed 

(Update 4/3/15)

Comments generated from the Staff plan review have been sent to the engineers

(Update 7/31/15)

Kennedy/Jenks has been tasked with preparing a Report of Waste Discharge.  Before a new NPDES (National Pollutant Discharge Elimination System) permit can be issued for the new plant, the Report of Waste Discharge must be completed.  The Report compiles all pertinent discharge information into a single document including descriptions of the service area, collection system, treatment facilities and effluent disposal and reclaimed water facilities.

Bid Set of Plans are now available (Update 8/25/15)

The "bid set" of plans are now available for pickup at your local Builders Exchange or at the MCSD office.  See the Bids & Request for Proposal tab located under General Info for more information. 

(Update 9/21/15)

A mandatory pre-bid meeting & site visit occurred on September 9th at 10 am.  Bids for the project must be received by October 22nd at 2pm.  The bid opening will occur at 2 pm on October 22nd.

(Update 10/30/15)

Bids were opened at 2pm on October 22nd.  The winning bid is currently under review by the engineers.

(Update 11/2/16)

Since the groundbreaking ceremony occurred on January 19 2016, the new plant upgrade has made a lot of progress.

From this...

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The Clarifiers have been poured and water tested.  The biosolids pond and aeration pond 1 have been lined. Electrical conduits have been installed to the lab and the concrete has been poured around them.  The maintenance building, Vac-con dump area and headworks are under construction. More frequent updates to follow.