Alderpoint Community Water District (ACWD) in Alderpoint, California, a remote community in southern Humboldt County, retained LACO to bring their water system into compliance with State Drinking Water Standards by addressing system deficiencies identified by the California Department of Public Health (CDPH).
ACWD extracts raw water for potable use from an infiltration gallery located within the western bank of the Eel River. In 1992, ACWD received a certified letter from CDPH notifying them that their water source has been classified as groundwater under the direct influence of surface water, and that the system was in violation of the Enhanced Surface Water Treatment Rule (ESWTR). Furthermore the exisitng 100,000 and 5,000-gallon water tanks were leaking badly and in danger of failing.
The water system was designed in 1965, and it serves approximately 219 residents and commercial users comprising 79 individual water service connections.
LACO provided engineering, surveying, geotechnical, and environmental review, and grant funding assistance services to help bring ACWD’s system into compliance and improve their infrastructure. Our project team served ACWD from the initial investigation stages of the project through final design and bidding assistance. We have completed the following items as a part of this project:
- Preliminary site and system investigations to determine the condition of the existing water system
- Site surveys, topographic mapping, and utility and easement locating to develop topographic site plans for the proposed treatment facility, and the existing and proposed transmission main alignment from the treatment site to the 100,000- gallon tank at the storage site
- An Engineering Report that determined the system needs to bring it into compliance with the State of California Title 22 standards and the ESWTR
- Submitted plans to CDPH for compliance review and incorporated their comments into the plans and specifications
- Contract bid documents, construction plans, and technical specifications detailing the needed improvements. The report also defined the following:
- Treatment system and storage needs, operational description, proposed site layouts, figures, and schematics
- Potential environmental concerns
- Other information directly related to meeting ESWTR treatment requirements and Prop 50 funding eligibility
- Geotechnical exploration of the storage tank and new treatment plant site, as well as along the pipeline alignment between treatment and storage sites
- CEQA documentation and permitting requirements, which included an Initial Study (IS), leading to a Mitigated Negative Declaration (MND), and a biological/wetlands study and report, among other special studies
- 75%, 100% and Final Design Plans, Specifications, & Engineer’s Opinion of Costs
- Proposition 50 grant funding assistance
- Bid solicitation and recommendation
Project construction began in December 2013, and LACO is currently providing the following construction phase services:
- Construction management and administration
- Engineering field observations
- Materials testing and special inspection, including subgrade inspection, soil compaction testing, concrete field sampling and testing, and concrete cylinder lab testing for compressive strength
- Labor Compliance Program (Prevailing Wage verification)
- Storm Water Pollution Prevention Plan (SWPPP), including submittal of the Notice of Intent (NOI) and Notice of Termination (NOT), and stormwater monitoring/sampling
- Funding Administration and claims processing
Temporary infrastructure was installed to reduce interruptions to the community’s water service during construction of the new tank and treatment system. The combination of temporary and permanent piping limited ACWD to one complete system shutdown lasting less than 10 hours, as well as two separate interruptions in service to a few localized customers. Keeping the system operational was particularly difficult because there were few operational valves in the distribution system, and there were no valves to isolate the existing redwood tank.