CURRENT PROJECT STATUS:
The City of Longview and Beacon Hill Water & Sewer District (BHWSD) currently supply customers with drinking water sourced from groundwater wells and treated at the Mint Farm Regional Water Treatment Plant (RWTP). The Mint Farm RWTP reliably produces drinking water that meets all regulatory standards. But when a 2014 survey found that a large majority of water customers were unsatisfied with their water, the City and BHWSD undertook a study of water quality improvement options. The study was completed in 2016, and considered more than 50 different options to modify the water supply and improve water quality. Switching the water source from Mint Farm groundwater wells to Cowlitz River horizontal collector wells was initially identified as a preferred alternative. However, disappointing water quality testing results caused this approach to be removed from consideration in July 2016 and focus shifted to optimizing groundwater at the Mint Farm.
In July, 2017 the City and BHWSD reviewed options to remove silica from the Mint Farm water and considered the cost to build and maintain the additional treatment processes which would be required. Based on an average increase of $12 to $15 per month for a typical single family household, the decision was made not to remove silica. This decision may be revisited in 2018 after seeing what benefit is gained by adding dissolved oxygen to address lingering taste and odor issues.
In August, 2017 the City and BHWSD awarded a construction contract to install an air injection system at the Mint Farm water treatment plant to increase the level of dissolved oxygen. Aeration is simple and widely used for corrosion control but provides a number of other benefits. Through testing, we found that dissolved oxygen will harden pipe scale and reduce iron release in the water distribution system. Aeration also removes hydrogen sulfide and ammonia, which cause taste and odor issues. Construction is expected to be complete in early 2017 but it will take several months to slowly increase the amount of dissolved oxygen being added to reach our target level. Once implemented, the long term goal is to reduce the amount of chlorine needed in the water treatment process, and to maintain a stable distribution system.
Horizontal Collector Well Feasibility Study
Exploratory wells were drilled in January, 2016 to evaluate three possible sites where a horizontal collector well could be located on the Cowlitz River - Fishers Lane, West Side Hwy at Solomon Road, and Riverside Park. Of the three, Riverside Park was determined to be the preferred site but the distance to either of the City's existing water treatment facilities and a hope for better water quality prompted the City to explore a fourth site in south Lexington opposite Rocky Point. In the end, Riverside Park and Rocky Point both proved feasible in regards to capacity but water quality testing showed high levels of iron, manganese, hardness and silica, the same constituents which have caused many of our current customer complaints. For a brief summary of the drilling results, basic water quality summary or to download a copy of the complete reports, click on the links below:
Customer Advisory Committee
In 2015, the Longview City Council and Beacon Hill Water & Sewer District commissioners appointed a Customer Advisory Committee (CAC) to recommend a preferred water supply option for the community. After reviewing all available options, the CAC recommended developing a new source on the Cowlitz River using horizontal collector wells. In March, 2016 CAC reconvened to discuss the results of exploratory well drilling and recommended we continue investigating the Riverside Park and/or Rocky Point sites. For more information about the CAC and its objectives, visit www.LongviewWater.org.
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Frequently Asked Questions:
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Water Fact Sheets:
Please check out these links to read fact sheets prepared by Intertox Inc., an independent toxicologist expert with information about water minerals:
News From the Well:
Please check out these Daily News inserts for water quality updates provided to customers:
Please check out the following presentations regarding updated water quality information, by clicking on the following links.
Public Outreach Documents:
Please check out the following handouts for tips on inspecting your hot and cold water plumbing system and other questions circulated in bill stuffers and the local paper addressing water quality concerns.
Letters from Concerned Citizens:
Formal letters from City staff responding to questions and concerns about issues relating to the Mint Farm groundwater source and water quality.
Distribution System Water Quality
To better address water quality issues, the City regularly samples the distribution system to monitor changes in customer water quality. More information is available by clicking on the following links:
Distribution System Sampling Location Map
Distribution System Sampling Plan and Data Record
Other Related Project Information and Reports:
- Wellhead Protection Program
- 08.01.2017 Softening Alternative and Baltimore Street Water Quality Evaluation - A comprehensive report by Confluence Engineering Group summarizing the evaluation and findings of numerous water quality investigations and mitigation strategies including main cleaning operations (ice pigging), enhanced water quality monitoring, bench-scale studies for phosphates, pipe loop trials for dissolved oxygen, characterization of white spot formation, treatment for silica removal, an assessment of organic nitrogen, and in-home water quality profiling. Appendices include:
- 05.18.2017 Silica Removal Alternatives Evaluation - A report by CH2MHill describing the treatment technologies available to remove silica including a discussion of capital, operating and annual maintenance costs and an evaluation of the preferred alternative(s).
- 05.18.2017 Silica Removal Alternatives Attachments - Water quality results and technical documentation containing results of the bench-level pilot studies performed by CH2MHill and WaterTectonics to evaluate treatment options for silica removal.
- 03.09.2016 Organic Nitrogen Removal - A technical memorandum explaining the test methods and results of work done to evaluate interim measures to remove organic nitrogen which could help address issues related to chlorine taste and odor.
- 07.29.2015 Home Plumbing Study - Results of water quality profiling done at two residential homes to better understand if the chemistry of the water changes between the distribution system main and the customer's tap.
- 06-25-2015 Chlorine Demand and Decay (CDD) Study - A comparison of chlorine demand and decay characteristics of each production well to determine which well has the most stable free chlorine residual and least tendency to result in combined chlorine species.
- 04-27-2015 Flavor Rating Assessment - Results of taste and odor testing performed by Seattle Public Utility to rate Longview's drinking water for offensive taste and odors.
- 06-06-2014 Silica White Paper - Provides background on silica and summarizes treatment options to remove it. This paper is not intended to provide an exhaustive review on silica but does provide an overview of the key aspects of silica chemistry which are necessary to evaluate the feasibility of treatment options for silica removal.
- 11-18-2013 Tracer Study Report - A report submitted to the Washington State Department of Health in compliance with the Groundwater Rule describing the results of a chlorine contact time tracer study and demonstrating CT6 for 4-log treatment at the Mint Farm Regional Water Treatment Plant.
- 09-14-2012 Mint Farm Wellfield Source Approval (less appendices) - In accordance with WAC 246-290-139, this report was submitted to the Washington State Department of Health for regulatory approval of the Mint Farm production wells for our drinking water supply. It summarizes the initial planning, engineering and hydrogeological evaluation leading up to construction and well logs and water quality information for each of the four wells.
- 09-14-2012 Mint Farm Wellfield Source Approval (with full appendices).
- 08-23-2012 Owners Distribution Water System Start-Up Plan - Start-up of the new Mint Farm Water Treatment Plant will change the direction of flow in some areas of the existing distribution system. This flow reversal, and the change from a surface water source to a groundwater source, can create potential problems if measures are not taken in advance of commissioning the new plant. This plan describes proactive efforts to flush the distribution system to remove scale, reservoir cleaning, water modeling, pH adjustment to match water chemistry, increased monitoring and utilization of citizen sentinels to provide early detection of water quality issues.
03-29-2011 Mint Farm WTP Corrosion Control Report
- EPA published the Lead and Copper Rule (LCR) in 1991 to reduce lead and copper levels in water by reducing the corrosivity of the water in the distribution system and reducing the corrosion of plumbing materials containing lead and copper. This report presents the City’s strategy to control corrosion in compliance with the LCR once the Mint Farm Water Treatment Plant is in operation.
- 03-14-2011 SEPA Amendment for Pipeline Re-Alignment - In accordance with SEPA rules and WAC 197-11, the change in alignment for the transmission main was also submittal for SEPA review.
- 03-02-2011 NEPA Amendment for Pipeline Re-Alignment - Finding of No Significant Impact (FONSI) for the Mint Farm Regional Water Treatment Plant was issued on August 13, 2010. The purpose and need of this action has not changed but an amendment was issued when it became necessary to seek an alternative alignment for the transmission main due to difficulty in acquiring easements along the railroad. Except for its location, the details of the transmission main as described in the original Environmental Information Document (EID) remain the same.
- 08-13-2010 NEPA Finding of No Significant Impact (FONSI) - The Environmental Protection Agency (EPA) conducted an environmental review of the proposed Mint Farm water treatment facility and issued a preliminary determination that the project will not result in significant adverse effect (direct, indirect or cumulative), meets all requirement of applicable federal, state and local laws, regulations, statues and Executive Orders and is consistent with the Cowlitz County Comprehensive Plan and Growth Management Act.
- 08-13-2010 NEPA Environmental Impact Document (EID) - The EID contains a detailed description of the proposed project (preferred alternative), the no action alternative and other alternatives considered but rejected. It evaluates effects on human and natural environment including wetlands, coastal zones, archaeological and cultural resources, floodplains, endangered species, air and water quality, and proposes mitigation measures to minimize impact.
- 07-19-2010 Pilot Study Summary - A summary of a follow-up 4-week pilot study performed in May, 2010 to confirm the performance of greensand granular media filtration using water drawn from deep monitoring well DW-9. The raw water quality at DW-9, located at the site of the future production wells, is lower in iron, manganese and arsenic compared to the original Prudential Blvd test well.
- 06-07-2010 Mint Farm WTP Geotechnical Report - A report summarizing the field work and results of the geotechnical study, including sub-surface investigation, exploratory borings and laboratory testing, for the proposed Mint Farm Regional Water Treatment Plant and associated transmission main to connect the plant to the City’s existing distribution system.
- 03-2010 Preliminary Design Report (PDR) - A comprehensive report which provides a history of the water supply project, why it's necessary and what's been done to investigate it. Part 1 provides background about the Fishers Lane plant, work done to investigate groundwater options and a description of the Mint Farm facility. Part 2 provides a detailed aquifer characterization, flow patterns developed through extensive modeling, and water quality information. Part 3 describes the initial findings associated with the NEPA permitting process. The appendices is available by request.
- 03-08-10 Environmental Site Assessment - Detailed report describing the environmental investigation focusing on identifying the potential for on- or off-site environmental conditions to impact the Mint Farm well field. The study includes an in-depth review of historical activities, file review with regulatory agencies, site reconnaissance and extensive lab analysis of numerous soil and groundwater samples taken from the Mint Farm.
- 01-04-10 Human Health Risk Assessment - A focused assessment of the water quality of three raw water sources available to this area - samples were collected from the Cowlitz River, Columbia River and Mint Farm aquifer and analyzed for more than 300 analytes. This report compares the three sources and evaluates whether the groundwater source is a safe supply of drinking water.
- 11-21-2009 - Project Map - A concept map showing the basic site layout for the new water treatment plant and proposed well field.
- 11-21-2009 - Vicinity Map - A concept map showing the basic site layout for the new water treatment plant and proposed well field.
- 09-02-2009 Mint Farm Groundwater Granular Media Study Report - The results of a 5-week pilot study using generic equipment to treat raw water pumped from the Prudential Blvd test well and determine whether iron, manganese and arsenic could be successfully removed using three types of conventional granular media.
- 05-02-2009 Mint Farm Groundwater Pilot Study Protocol - The plan developed for water treatment trials describing the pilot study equipment, how it will be operated, treated water quality goals, and outlining the sampling and analysis plan for the raw and treated waters.
- 04-28-2009 Water Quality Sampling and Analysis Protocol - A plan describing where and how samples will be collected to evaluate the Mint Farm source – soil samples from the Mint Farm Industrial Park, groundwater samples from the Mint Farm aquifer (deep and shallow), as well as other available surface water sources (Cowlitz and Columbia Rivers). The plan also provides an analyte list for testing based on current regulation, emerging contaminants which may be regulated in the future and unregulated contaminants common to historical and industrial activity near the Mint Farm.
- 04-03-2009 Shallow Monitoring Well Construction Report - A summary of the drilling activity for the construction of the first set of shallow monitoring wells. Provides the location, drillers well report, construction details and geologic log for wells SW-1 through SW-7.
5-7-2008 - Constructability Study - A summary by Kennedy/Jenks Consultants intended to provide the City of Longview with a decision-making tool to determine whether the Regional Water Treatment Plant could be accomplished efficiently and effectively. Also, it identifies deficiencies, needed improvements, cost estimates, and a schedule for implementation.
- 05-05-2008 - GSI Environmental Review - A third party environmental review of the area near the proposed well field in the Mint Farm looking for existing potential contaminant sources due to industrial and commercial operations, and existing wells with poor surface seals. The report evaluates the potential risk of contamination to the deep aquifer from those potential sources.
- 01-09-2008 Columbia River Water Quality Report - Laboratory report with results of the analysis of untreated water samples collected from the Columbia River. Reports raw data from analysis of inorganic compounds (IOC’s), volatile compounds (VOC’s), synthetic organics compounds (SOC’s), herbicides and some unregulated contaminants.
- 12-14-2007 - GSI Peer Review - Provides a second opinion of the groundwater evaluation provided by Robinson, Noble & Saltbush in their 01-2007 Prudential Blvd Test Well Report which included preliminary conclusions about the Mint Farm aquifer based on the original test well. The GSI peer review focuses on whether the aquifer is productive enough to meet the City’s projected water demand and whether that supply can be sustained. Also provides discussion of the basic groundwater quality and issues related to siting the well field in an industrial area.
9-4-2007 - Value Engineering Study - Provides information by Smith-Culp Consulting regarding water supply alternatives to improve the Cowlitz River water. The main alternatives are to rehabilitate the sixty-year-old surface water treatment plant or relocate the wells and groundwater treatment plant to the Mint Farm Industrial Park.
- 01-2007 Prudential Blvd Test Well Report - A summary of the construction of the Prudential Blvd test well (formerly Weber Ave test well) which was the first exploratory well drilled in the Mint Farm. Describes the drilling, construction, testing, geology, hydrogeology and water quality at this location.