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Sandmound Rd Area - Water Quality

Current Systems Under County Compliance Order

Delta Mutual Water Company

M-27 (Willow Park Marina and Mariner Estates)

Oakley Mutual Water Company

Currently, the independent well (M-27) serving Willow Park Marina and Mariner Estates, is under a compliance order from Contra Costa Health Services to address elevated arsenic levels as of March 31, 2021.

The compliance order requires a permanent solution, engineered by the District, within the next three years. Quarterly notifications are also required to be sent to property owners.

All updates and documentation regarding current systems under a county compliance order will be found on this page.

Updated October 17, 2023: The second Public Outreach Meeting was held on Thursday, September 7, 2023, at Scout Hall in Bethel Island.  The public was invited to come engage, ask questions, and provide input about the potential voluntary opportunity for small water systems to connect with Diablo Water District.

Click here to access the minutes for this meeting.

If you would like to receive an email notification for future meetings, please contact Kait Knight at


Where are the pipes on Sandmound being installed?

Pipeline will be in the Right of Way (see minutes for map of area).

How and when will connections take place on Sandmound?

Approximately three years until the start of construction, based on the anticipated time to complete the application and State Board agreement.

Can existing wells be kept for irrigation purposes? Would that conversion be paid for?

Each mutual will decide what to do with their wells. The grant will not cover converting the wells for irrigation but could potentially cover well abandonment, which is costly.

How come Beaconwest has DWD water?

Beaconwest was connected under emergency for arsenic exceedances that increased to the point that action needed to be taken; customers had to pay for the emergency pipeline, since no grant funding was available to them at the time.

Why is Bethel Island not already in DWD’s Sphere of Influence (SOI), but Delta Coves is?

The SOI is regulated by LAFCO. The District’s SOI was amended to include Delta Coves as their wells were unable to meet drinking water standards. The CVP allocates some of our water, and there is a federal inclusion process to annex parcels that takes about a year.

Why is my water on Bethel Island degrading after the past 25 years of use?

Factors such as high groundwater, septic systems, aging infrastructure, and changes in regulatory levels have caused degradation of water quality.

How will each decision to participate or not be made by each water system? What if we do not want to consolidate?

Each water mutual/private well owner will have to make that decision themselves. Each mutual’s bylaws for voting will determine if they opt in or out. If a group does not participate in the consolidation project, they will need an action plan to resolve the primary exceedances and correct their water quality issues, which will be enforced by the County.

Anyone needing free assistance with their bylaws can contact Toby Roy at

Are we going to be assessed on our taxes?

For this grant, the District is pushing for 100% grant funding. Anyone can opt out, but with the study, you are going to get more information about your water system. We want the community to be informed before making a decision. The feasibility study will be 100% grant-funded.

What will be the anticipated costs for each homeowner?  What parts of construction would they be responsible for?

For this grant, the District is pushing for 100% grant funding. Currently, the grant does not cover the back of the meter to the home.

I’ve heard rumors that this could possibly cost each person $10k- is that true?

In the past, there have been issues with grant funding not covering everything.  The District is trying to get both projects to be 100% grant-funded, but there is no guarantee until a contract with the State is signed. The District is working to expedite the grant. We encourage mutuals and well owners to remain involved in the process to learn what costs will be covered.

What are DWD’s monthly water fees?

DWD has the lowest water rates in the area. Fees pay for everything- replacing main and meters etc. A typical residential 5/8” meter has a monthly service charge of $20.44, while water rates start at $3.05 for every cubic foot (748 gallons). There are also conservation programs and rebates available, as well as income-based discounts on the monthly service charge.

What is the current status of the projects?

As part of the planning, a Preliminary Engineering Report outlining the proposed improvements for the consolidation will be finalized in the near future. This will be followed by the development of plans and specifications, preparation of environmental compliance documents and a construction grant application. A construction grant application will be submitted to request Drinking Water State Revolving Fund (DWSRF) construction funding by approximately October 2024. It is then expected to take the Water Board approximately 9-12 months to enter into a grant agreement with DWD. Construction could commence in late 2025.


Previously Held Meetings

  • An initial kick off call was held on Wednesday, November 17, 2021. This was hosted by RCAC along with Diablo Water District. Please contact Kait Knight, at (925) 625-6587 with any questions.  You can watch the meeting here.  Monthly follow up meetings will be held throughout the initial phase of this Technical Assistance.
  • A Special Board Meeting was held on Monday, May 10, 2021 where the greater Sandmound Rd area water quality and community water systems update and discussion took place.  Please visit our Board Agendas and Minutes page for more information.