Recommended Action
To realize a savings of $150,000 to $300,000 in the cost of constructing the North Davis Meadows Water Connection Project, approve fourth amendment to agreement with West Yost Associates increasing the contract by $22,000 for additional design services related to a reduced fire flow requirement (more detail provided below).
Background
Since 2009, the North Davis Meadows CSA has been working toward a permanent solution for mitigation of water quality issues in the community's public water system, most notably nitrates, hexavalent chromium, aluminum and iron in excess of maximum contaminant levels (MCLs). Absent progress toward a viable solution, the community is at risk for $1,000 fines per day, per constituent over the MCL (currently $3,000 per day absent an MCL for hexavalent chromium). After assessing a variety of options for providing a potable water supply that meets all drinking water standards, including treatment at the well-head (initially considered when only nitrates were of concern and deemed to be too costly to install and maintain given the utility costs and hazardous waste disposal costs) and drilling deep wells, the County, North Davis Meadows CSA Advisory Committee and the community concluded consolidating with the City of Davis public water system was the most reliable and cost-effective method to comply with California drinking water regulations and to ensure the health and safety of the residents North Davis Meadows (see chart below estimating current well and treatments costs vs. the current City of Davis connection project).
On September 27, 2016, the Board of Supervisors approved an agreement with West Yost Associates for the design work related to extending City of Davis water to the North Davis Meadows community for indoor uses only, as was the desire of the community following a June 2015 survey. Design commenced in December of 2016 and was almost complete by summer of 2017. As with many projects of this nature, circumstances changed and new information compelled the North Davis Meadows community to re-evaluate the path they were on and consider alternatives. Most notably, the City of Davis Fire Chief had a strong recommendation that water for fire protection come from the City of Davis water system. In addition, new information emerged related to costs to maintain/upgrade the existing wells which would have been used for irrigation and fire protection. Finally, the City of Davis water usage rate structure had been revised to reduce rates below those considered in the past (today estimated at $3,650/year/parcel based on average use in Davis, Willowbank and El Macero in 2016, utilizing 2018 rates and considering NDM lot sizes are approximately 2.25 times the average lot size in El Macero).
Three scenarios related to consolidation with the City of Davis were studied and the estimated costs, benefits and risks shared with the community (Attachment A). In the fall of 2017, the community was surveyed on their new desired path. The survey was completed by a majority of households in the community with the majority of respondents favoring connecting to the City of Davis for all water uses (Attachment B). An amendment to the contract with West Yost was approved to allow for the additional work necessary to perform hydraulic modeling of the expanded water system, additional pot holing necessary to complete design and development of 100% design drawings, and specifications and cost estimates incorporating the new requirements. To accommodate these scope changes, construction phase support services were deleted. On March 20, 2018, another amendment to the contract was approved to reauthorize construction phase support for the redesigned project and include other additional engineering services required for completion of the project.
Also on March 20, 2018, Proposition 218 proceedings were conducted to increase the CSA's annual water fee by $4,157 to repay an anticipated $8.25 million low-interest State Revolving Fund loan over 30 years to fund construction of the connection to the City of Davis public water system. A majority of the parcels within the neighborhood did not file protests and the Board of Supervisors approved the water fee increase by a 5-0 vote.
Following the Proposition 218 proceedings, a letter was sent to all residents explaining the outcome and an invitation was extended to a community meeting to further clarify some of the issues raised during the proceedings. The meeting was conducted and experts from the County and State were brought in to answer questions. Ultimately, a commitment was made to further evaluate the costs and risks of the following alternatives of interest to some in the community: Alternative A) a dual use system that would connect irrigation systems to the community's wells; Alternative B) new drinking water wells with infrastructure upgrades; and Alternative B+C) treatment via Point of Use. This evaluation was funded by the County Administrator's Office and conducted by Elisa Sabatini, Manager of the Natural Resources Division. The results of the evaluation determined there was no viable, long-term alternative to the approved project. The results were shared during another community meeting and mailed to each property owner. See Attachment C for the report and presentation on the current water project and two alternatives.
Along the way, numerous meetings were held with groups of those in support and opposed to the approved project with additional information requested, gathered and provided to the community. One request was for the process, timeline and estimated costs for a Proposition 218 fee procedure to fund an exploratory (monitoring) well to identify whether clean, reliable water is available in the aquifers available to NDM (Attachment D). Research into such an exploratory well with local experts further underscored the risk and uncertainty of drinking water wells, particularly given the likelihood of ever more stringent State regulations in the future, and as such, the expense (estimated $200,000) of proceeding with an exploratory well is not recommended.
Costs Estimates for New Wells & Treatment vs. Current Project Connecting to City of Davis Water
| |
Construction Costs |
Ongoing Annual O&M |
| Monitoring Well |
$200,000 1 |
N/A |
Two 1,800 ft. Deep Wells
(two wells required for redundancy; both required to individually meet fire protection requirements - see notes below) |
$4.6-6.3 million 2 |
$190,000 |
| Well Head Treatment 3 |
$2 million/500 gpm well
$4-8 million/2,000 gpm well |
$80,000/500 gpm well
$150,000/2,000 gpm well |
Total Estimated
Well-Related Costs
(See notes re: well size) |
$10.5-16.8 million 4 |
$420,000 |
| |
|
|
Current Project
City of Davis Connection |
$8.3 million |
$365,750 5 |
1 Rough estimate from 09/17/18 meeting with Luhdorff Scalmanini Consulting Engineers
2 Rough estimate derived from 2010 and 2012 engineering memos; likely needs to be adjusted to account for increases in labor costs (+20%) and the price of steel (+30%) per Dan Morris, Eaton Pumps
3 Rough estimate based on wellhead treatment assessment commissioned by the City of Winters in 2016
4 Does not include upgrading pipes for increased flow, fire protection improvements, future capital replacement costs per Luhdorff Scalmanini and West Yost Associates
5 Based on City of Davis estimates of water usage for average NDM parcel considering 2018 rates ($3,650/year/parcel)
Notes regarding well size:
- Two wells are required for redundancy
- The lower gpm (gallons per minute) well would require additional infrastructure to address the City of Davis requirement for 1,000 gpm fire flow (i.e. storage tank and booster pump)
- Fire flow requirements consider taking the highest producing facility offline during a fire event, or in other words, each well would need to be able to satisfy fire flow requirement by itself. As a result, both wells would have to accommodate 1,000 gpm.
- A 2,000 gpm well is likely larger than needed, but cost estimates related to a 2,000 gpm well were readily available
Also requested and shared with the community were the project costs expended as of July 6, 2018 (Attachment E). As of that date, $710,890 were extended by the County on this project, with only $56,620 collected from the residents for repayment. An additional $119,733 of expenses was anticipated, an amount which has risen in response to numerous resident requests for information. Requests for information have included historical data related to Davis wells, various assessments of North Davis Meadows wells, and the irrigation (ag) well permit process, etc. There has also been a request to explore options to assist low-income residents with costs related to this project which is currently in progress. All information gathered to date and provided the community has been posted to their Water Connection Project webpage on www.YoloCounty.org/North-Davis-Meadows-CSA.
Meanwhile, as the approved project is believed to be the best solution for reliable drinking water and fire protection for the residents of North Davis Meadows, staff is diligently working with the State on a timely review of an extensive and comprehensive application for a low-interest State Revolving Fund loan for the planning and construction of a connection to the City of Davis public water system as the CSA's current public water system does not provide safe drinking water, and interest rates and construction costs are rising.
Recommended Action
The Water Connection Project is currently designed to the City of Davis standard of 1,500 gallons per minute fire flow for one hour, with a residual system pressure of 20 pounds per square inch gauge. Subsequent to completion of the water system modeling and preparation of the plans, specifications and estimates for the project, representatives of the City of Davis and the County discussed the project requirements specific to fire protection and determined the fire flow requirements for the North Davis Meadows neighborhood could be reduced to 1,000 gallons per minute fire flow. With this reduction, it is estimated there could be a savings of $150,000-300,000 in construction costs. The recommended action is to approve a fourth amendment (Attachment F) to the contract with West Yost Associates, increasing the compensation by $22,000 and authorizing the work necessary to perform the additional hydraulic modeling of the water system with the new fire flow requirements and the resulting modification of the water system improvement plans, specifications and estimates. |