CURRENT PROJECT STATUS:
The Mint Farm Regional Water Treatment Plant is reliably treating groundwater to produce high quality drinking water. However, in response to hard water complaints and white spotting issues, City staff has evaluated alternatives to soften the water and remove dissolved silica, the primary contributor to spotting. Options to remove silica at the treatment plant include reverse osmosis (RO), magnesium co-precipitation and alum coagulation, all three of which are very complex and expensive technologies ranging from $35 million to $81 million. Additional options are being explored and City Council has directed staff to revisit surface water options.
The release of scale in the distribution system continues to decline as the system approaches a state of equilibrium. Extensive sampling is ongoing but the distribution system chemistry has improved and is stabilizing. Additional water main replacements are being planned in areas which require ongoing flushing or other pipe cleaning options in order to maintain water quality. An outside expert toxicology assessment confirmed no adverse health effects are expected from silica, hardness (calcium and magnesium), iron and manganese at the concentrations measured in our water. Protection of public health continues to be our number one priority.
Frequently Asked Questions:
Click here to view our new frequently asked questions document. Water questions and answers
View the Water Quality table referred to in question one in the Water Questions and Answers document by clicking this link.Table 4.1 WQ Summary
Water Fact Sheets:
Please check out the following fact sheets prepared by Intertox, Inc. (an independent, third party firm) regarding toxicology of water minerals, by clicking on the following link.
News From the Well:
Please check out “News from the Well”, a document that provides water utility updates for the City of Longview, by clicking on the following link.
Please check out the following presentations regarding updated water quality information, by clicking on the following link.
More information: Other questions? Click to view Frequently Asked Questions.
Public Outreach Documents:
- Meter to Tap
The City of Longview wants to help you maintain high-quality water throughout your household plumbing system. Use this brochure yourself, or use it to work with a licensed plumber, to inspect your cold and hot water plumbing systems and identify areas for improvement. Follow the 10 simple tips to help ensure your tap water quality and understand how water quality is affected by the plumbing conditions in your home.
September 2013 Bill Stuffer
This bill stuffer was included with September 2013 utility bills to provide customers with an update on the status of the drinking water distributed by the Mint Farm Regional Water Treatment Plant. It discusses the origin and effects of hard water in general and specific characteristics of the City’s water source to help customers understand the factors contributing to noticeable changes in water quality.
December 2009 Bill Stuffer
This bill stuffer was included with December 2009 utility bills during the planning stage of the project. Concerns regarding the groundwater source, sustainability, and safety are addressed. Water source information and an overview of preliminary test methods and results is also provided.
This newsletter was distributed to Longview citizens in the City’s local newspaper during the planning stage of the project. It explains the need for expanding treatment capacity based on demand and increasing sediment buildup in the Cowlitz River. Two options are discussed in the newsletter: rebuilding the Fishers Lane Regional Water treatment plant and constructing a new treatment plant at Mint Farm Industrial Park. This newsletter summarizes the in-depth analysis and results leading up to the final decision to pursue the new groundwater source and treatment facility at Mint Farm.
Related Project Information and Reports:
- 06-06-2014 Silica White Paper - The purpose of this white paper is to present background information on silica chemistry, to summarize information concerning silica treatment alternatives, and to discuss potential silica deposit modification alternatives. This document is not intended as an exhaustive review of the literature pertaining to silica, but rather as an overview of the key aspects of silica chemistry that may provide insights on the feasibility of removing silica from the water and methods customers of the City of Longview could use to reduce white spotting.
- Distribution System Sampling Location Map - This map shows sampling locations for the distribution system in regards to water quality monitoring for the City of Longview.
- Distribution System Sampling Plan and Data Record - This spreadsheet shows a summary of analyte testing for the distribution system in regards to water monitoring for the City of Longview.
- 04-17-2013 Water Quality Report Nov-2012 Sampling Event - This report summarizes the results of groundwater monitoring and sampling event conducted in November-2012 in the Mint Farm well field area just prior to start-up of the Mint Farm Water Treatment Plant in January-2013. Groundwater samples collected from deep sentinel wells DW-1, DW-2, DW-5, DW-6, DW-7, and DW-9 during this final pre-operating semi-annual sampling event establish the baseline groundwater quality prior to full scale water production from the Mint Farm wellfield.
- 06-28-2012 Water Supply Protection Ordinance No. 3209 - Water Supply Protection ordinance supplements the WHPP, with provisions to minimize the risk of potential water supply contamination and provide a means of enforcement, but which also allows economic development that does not present an unreasonable risk to the City’s water supply. By adopting the ordinance, the City also committed to providing education and technical assistance to businesses, industries and the general public to explain how to implement water resource protection and pollution control practices. Staff continues to work with Cowlitz County and Columbia County, Oregon, to adopt similar wellhead protection measures to protect the water supply.
- 02-09-2012 Wellhead Protection Program - To protect the new groundwater source and comply with Washington Administrative Code (WAC) 246-290-135 (3), a Wellhead Protection Program (WHPP) was developed. The Department of Health approved the draft Wellhead Protection Plan in March 2010 and the final version was incorporated in the 2012 Water Master Plan Update. Elements of the WHPP include:
- Susceptibility assessment for each well.
- Wellhead Protection Area delineating the 6–month, 1-year, 5-year and 10-year time of travel zones.
- Inventory of known and potential groundwater contaminant sources within the WHPA.
- Notification of the WHPP to owners/operators of the potential contaminant sources in the WHPA.
- Notification to regulatory agencies and local governments of the WHPP and potential contaminant inventory.
- Notification and coordination with local emergency responders regarding the WHPP.
- Contingency plan to ensure adequate drinking water supply in the event of contamination.
11-13-2012 Water Quality Report July-2012 Sampling Event
- This report summarizes the results of groundwater monitoring and sampling event conducted in July-2012 in the Mint Farm well field area. The groundwater monitoring and sampling is conducted on a semiannual basis to establish background water quality in the deep aquifer prior to initiation of full scale water production from the City’s proposed well field. Groundwater samples are collected from deep sentinel wells DW-1, DW-2, DW-5, DW-6, DW-7, and DW-9 during each pre-operating semiannual sampling event. These wells were selected based on their locations relative to the industrial facilities in the vicinity of the Mint Farm.
09-14-2012 Mint Farm Wellfield Source Approval Document - In accordance with WAC 246-290-139, this report documents the information required by the Washington State Department of Health for regulatory approval of the four productions wells constructed at the Mint Farm for City of Longview municipal drinking water supply. It provides a summary of the initial planning, engineering and hydrogeological evaluation leading up to the project and comprehensive information about the construction and water quality of each well. For information referenced in the appendices, figures and exhibits, please contact the Engineering Department.
- 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 precautionary measures are not taken in advance of commissioning the new plant. This plan describes the proactive efforts taken and proposed by the City to flush the distribution system piping to remove scale, clean its reservoirs, model the changes in flow conditions, adjust pH levels to match the chemistry of the two water sources, increase monitoring efforts and utilize citizen sentinels to promote early detection of water quality issues.
- 06-16-2012 Water Quality Report - December 2011 - This report summarizes the results of groundwater monitoring and sampling event conducted in December-2011 in the Mint Farm well field area. The groundwater monitoring and sampling is conducted on a semiannual basis to establish background water quality in the deep aquifer prior to initiation of full scale water production from the City’s proposed well field. Groundwater samples are collected from deep sentinel wells DW-1, DW-2, DW-5, DW-6, DW-7, and DW-9 during each pre-operating semiannual sampling event. These wells were selected based on their locations relative to the industrial facilities in the vicinity of the Mint Farm
- 09-07-2011 Water Quality Report May-2011 Sampling Event - This report summarizes the results of groundwater monitoring and sampling event conducted in May 2011 in the Mint Farm well field area. The groundwater monitoring and sampling is conducted on a semiannual basis to establish background water quality in the deep aquifer prior to initiation of full scale water production from the City’s proposed well field. Groundwater samples are collected from deep sentinel wells DW-1, DW-2, DW-5, DW-6, DW-7, and DW-9 during each pre-operating semiannual sampling event. These wells were selected based on their locations relative to the industrial facilities in the vicinity of the Mint Farm.
- 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 new Mint Farm Water Treatment Plant is in operation. In combination with this, the City is also developing a separate planning document to maintain water quality in the distribution system with improved flushing.
- 03-14-2011 SEPA Amendment for Pipeline Re-Alignment - In accordance with the SEPA rules and WAC 197-11, the change in alignment for the water transmission main was also submittal for SEPA review.
- 03-10-2011 Water Quality Report Nov-2010 Sampling Event - This report summarizes the results of groundwater monitoring and sampling event conducted in November 2010 in the Mint Farm well field area. The groundwater monitoring and sampling is conducted on a semiannual basis to establish background water quality in the deep aquifer prior to initiation of full scale water production from the City’s proposed well field. Groundwater samples are collected from deep sentinel wells DW-1, DW-2, DW-5, DW-6, DW-7, and DW-9 during each pre-operating semiannual sampling event. These wells were selected based on their locations relative to the industrial facilities in the vicinity of the Mint Farm.
- 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 water transmission main due to difficulty in acquiring easements. The transmission main was planned along the east side of the wetland mitigation area adjacent to the existing railway tracks but the proposed alignment has shifted to the west side of the wetland mitigation site within a City-owned 20-ft easement currently used to access the mitigation site. 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 water treatment facility at the Mint Farm and have issued a preliminary determination that the project will not results in significant adverse effect (direct, indirect or cumulative) to the human and natural environment and 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) - As a recipient of federal funding, the Mint Farm Water Treatment Plant project is subject to federal NEPA compliance with EPA acting as the lead review agency. The Environmental Impact Document (EID) contains a detailed description of the proposed project (preferred alternative), the no action alternative and other alternative considered but rejected. It evaluates the effect the project may have on the 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 the potential impact.
- 07-19-2010 Pilot Study Summary - A brief 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.
- 07-03-2010 Water Quality Report May-2010 Sampling Event - This report summarizes the results of groundwater monitoring and sampling event conducted in May 2010 in the Mint Farm well field area. The groundwater monitoring and sampling is conducted on a semiannual basis to establish background water quality in the deep aquifer prior to initiation of full scale water production from the City’s proposed well field. Groundwater samples are collected from deep sentinel wells DW-1, DW-2, DW-5, DW-6, DW-7, and DW-9 during each pre-operating semiannual sampling event. These wells were selected based on their locations relative to the industrial facilities in the vicinity of the Mint Farm.
- 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.
- Draft Preliminary Design Report - March 2010 - The PDR is a comprehensive report which provides a history of the water supply project, why it is necessary, what has been done to investigate it, and a description of the new facilities and method of treatment proposed to develop a groundwater source at the Mint Farm. Part 1 (Basis of Design) provides background about the existing water treatment plant and why groundwater is being considered as an alternative source of supply. It describes pilot study efforts done to confirm the groundwater could be effectively treated, the preferred method of treatment, and provides a preliminary layout of the proposed water treatment plant, processes and wellfield. Part 2 (Hydrogeology, Water Quality and Wellhead Protection) provides a detailed characterization of the deep aquifer, associated water quality, and how it can be protected. Subsurface investigations and complex modeling is used to interpret how the aquifer behaves, simulate the pattern of groundwater flow and evaluate the impact of long-term pumping. Part 2 also describes what is required of a Wellhead Protection Program to protect the source from potential contamination at the surface. Part 3 (Environmental Permitting) describes the initial findings and on-going work associated with the National Environmental Protection Act (NEPA) permitting process and archaeological investigation required as part of the project.
- 03-08-10 Environmental Site Assessment - Phase I and Phase II. Detailed report describing the environmental investigation of the Mint Farm Industrial park and related findings. The focus of the investigation was to identify the potential for off-site or on-site environmental conditions to impact development of the deep aquifer and proposed well field. The study included an in-depth review of historical activities, file review with regulatory agencies, site reconnaissance and extensive field and lab work to collect and analyze numerous soil samples and groundwater samples throughout the site.
- 01-04-10 Human Health Risk Assessment - A focused assessment of the water quality and potential risk to human health, if any, posed by the three raw water sources available to this area. Untreated samples collected from the Cowlitz River, Columbia River and Mint Farm deep aquifer were analyzed for more than 300 analytes including contaminants currently regulated by state and federal drinking water standards, contaminants expected to be regulated in the future, emerging contaminants (pharmaceuticals and personal care products), and chemicals specific to local industry. This report compares the three sources and evaluates whether the proposed groundwater is a safe source of drinking water supply.
- 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.
- 10-31-2009 Monitoring Well Location Map - A map showing the locations of the deep and shallow monitoring wells in and around the perimeter of the Mint Farm Industrial Park.
- 09-04-2009 Deep Monitoring Wells Construction Well Logs - A detailed record of the geologic formation of deep monitoring wells DW-1 through DW-9 based on visual inspection of the cuttings produced during drilling and physical measurement made by instruments lowered into the hole (E-Log).
- 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 the pilot study which describes the pilot study equipment and how it will be operated, establishes goals for the treated water quality, identifies the oxidants which will be used, and outlines the sampling and analysis plan for the raw water and treated water.
- 04-28-2009 Water Quality Sampling and Analysis Protocol - A plan describing where and how three different types of samples will be collected – soil samples from the Mint Farm Industrial Park, groundwater samples from the Mint Farm aquifer (deep and shallow), and other potential surface water sources (Cowlitz and Columbia Rivers). Also describes what each type of sample will be tested for based on current regulation, emerging contaminants which may be regulated in the future and unregulated contaminants common to historical and industrial activity in and around 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 & WATER QUALITY DATA - 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.