Water Supply Engineering

Scope of Work: Design of a surface-water supply system for a 40-megawatt energy-generating facility; coordination and monitoring of various contracted parties

Acheron designed the surface-water supply system for a 40-megawatt energy-generating facility in Livermore Falls, Maine, for Alternative Energy, Inc., (AEI) of Bangor. The system, which included an intake pipeline of approximately 500 gal./min. and a discharge pipeline of approximately 30 gal./min., traveled over 4,000 feet of land owned by various parties including AEI, International Paper (IP), and the Maine Central Railroad (MCRR).

Acheron first performed a site assessment for the system, examining the proposed route of the pipeline and proposed site of the intake structure. Acheron reviewed Federal Emergency Management Agency (FEMA) flood studies to determine flood levels on the Androscoggin associated with a 500-year event.

Acheron produced a preliminary design for review by AEI and for permitting purposes. A final design was then produced, paying particular attention to pipeline alignment and water-hammer analysis. Finally, Acheron conducted site visits during construction to observe progress and answer questions.

Of particular note for this project is the number of parties included. Three major industries, AEI, IP, and MCRR owned the land and had to provide easements. In addition, per AEI's request, Acheron relied on the surveying of Maine Land Development Consultants, Inc., (MLDC) and permitting of HMM Associates of Massachusetts. This coordination illustrates Acheron's ability and willingness to work with various parties toward the successful completion of a task.

Scope of Work: Design of a surface-water supply system for an energy-generating facility; upgrade design of existing intake pipe and assist in permit applications.

Acheron designed a surface-water supply system for an energy-generating facility in Ashland, Maine, for Alternative Energy, Inc., (AEI) of Bangor. The facility was constructed in the Ashland Industrial Park and required an intake of approximately 500 gal./min. of process water from the Machias River. The water was to be supplied by the Ashland Water District which would pump into an existing wet well for AEI to draw on. In order to accomplish this, the District's intake had to be upgraded. A pipeline of approximately 3,000 feet also had to be constructed on land owned by the Town of Ashland and AEI.

Acheron first conducted a site visit, to meet with representatives from the Water District, the Town, AEI and Northern Maine Concepts, the engineers for the Industrial Park Project. Acheron discussed site and river characteristics, as well as plans for the Industrial Park. Data was also reviewed. Acheron's survey crew then visited the site and acquired river cross-section data, pump-room layout information, and pipeline-route elevations. These survey data served as the basis for the design work.

Acheron produced a preliminary design including plans for the upgraded intake, pumping system, and pipeline. These plans were also used in the environmental permit applications. Because the Machias River is a Class AA Water, a Natural Resources Protection Act (NRPA) permit, an Army Corps of Engineers' permit and a Shore Land Zoning permit were required for the upgraded intake.

This project demonstrates Acheron's ability to work closely with other parties. It also demonstrates the Company's expertise in the permitting process.

Client: Central Maine Power Company

This long-term study involved identification of areas affected by a fuel-oil release that occurred over a sand-and-gravel aquifer resource. The location of the plume was identified by installation and sampling of 24 monitoring wells, 30 soil gas vapor probes, and three soil borings. Acheron designed and implemented a groundwater recovery plan involving operation of two (2)-6-inch diameter hydrocarbon recovery wells. Separate 24-hour and 76-hour pump tests were conducted to evaluate aquifer transmissivity and storativity and to assess the effects of contemporaneous pumping of the municipal water-supply and recovery wells.

Technique Summary:

Drilling: Twenty-seven soil borings and monitoring-well installations were completed.

Sampling: A long-term monthly sampling program is currently in effect for selected monitoring wells.

Aquifer Testing: Twenty-four hour and 76-hour constant-rate pumping tests were completed for analysis of aquifer parameters.

Soil Gas Survey: Thirty soil gas vapor probes were installed inside and out of the abandoned building to delineate the hydrocarbon plume.

Scope of Work: Performance of Phase I remedial investigation of chlorobenzene contamination of a Town's private bedrock wells

Scope of Work: Extensive sampling of area domestic wells, development and sizing of activated-carbon filters sufficient to treat each well

Scope of Work: Development of a comprehensive systems facilities plan for public water supply system.

Acheron was retained by Consumers Maine Water Company to develop a comprehensive system facilities plan for its Hartland Division. The facilities plan is a 10 to 20-year planning tool used to guide and plan the capital improvements program for the water system in Hartland. The plan is a single, comprehensive document that details and prioritizes system improvements, and their associated costs, needed to allow the water system to meet regulatory requirements and public health and safety concerns. The document provides the Town of Hartland with a comprehensive vision of what the water system will be in the future, describing future service areas and the level of fire protection the system will provide.

This project entailed the generation of updated maps of the water system, to provide a thorough picture of the existing system. A hydraulic model of the existing water transmission and distribution system was then be developed to serve as an evaluation and planning tool for the water system. With these tools, the water system was then assessed from an engineering, managerial, and financial standpoint. The model was used to evaluate existing system deficiencies and potential upgrades to address the deficiencies. Water system improvements were prioritized as short-term (0 to 5 years) capital improvements and long-term (6 to 20 years) capital improvements. An integral component of this assessment was financial planning that strived to maintain reasonable water rates for the community. To this end, Acheron evaluated the requirements of the various funding agencies and the availability of grants and principle forgiveness from each source.

The most critical issue faced by CMWC in Hartland is coming into compliance with the Surface Water Treatment Rule of the Safe Drinking Water Act. The system’s existing surface water supply, Starbird Pond, is used unfiltered. However, water quality of the pond is marginally unacceptable for a waiver from filtration.

As such, Acheron was tasked with evaluating water source options available in Hartland. This included continued use of the existing source or development of a new source. The assessment of continuing to use Starbird Pond included investigating alternative filtration technologies including package filtration systems and membrane filtration systems. These options were compared to the potential of developing a new groundwater source at three (3) possible locations. Cost estimates were developed for each of the source options to allow direct comparisons to be made and impacts on user rates to be assessed.

Lastly, the need to improve storage capabilities within the water system were assessed. A 500,000-gallon reservoir was calculated to be required and potential locations for the tank were evaluated. Based on Acheron’s evaluation, CMWC entered into a purchase-and-sales agreement with the owner of a highly desirable property. That location will allow CMWC to eliminate two (2) booster stations within the system.

Scope of Work: Analysis of groundwater sources and design and development of drinking water supply system

In 1995, several residences and businesses in the Town of Corinna, Maine, were discovered to have contaminated water supplies. The Town, which had no public drinking water supply and distribution system, retained Acheron to research the extent and nature of the contamination and design possible remediation. After conducting drinking water tests at several residences and businesses in the Town, it was discovered that the contamination was from chlorobenzenes and was localized. As a temporary solution, filters were added to the affected wells.

Acheron and the Town decided that a long-range solution would be the design and construction of a drinking water supply and distribution system. Acheron conducted hydrogeologic studies to locate a suitable well. Acheron then utilized Waterworks, a computer modeling program, to design a pump station and distribution system. The Town decided to limit the system to the residences and businesses with contaminated water but planned to someday expand the system to include the entire Town. Given these present and future plans, Acheron modeled and designed a system that would serve the entire Town including a fire protection system. Only a small section of the system was built at this time, but since current construction was limited and future construction was facilitated in the design, the Town saved money.

Acheron assisted in obtaining residential and railroad easements. Acheron also obtained a National Resource Protection Act Permit-by-Rule for a river crossing. Funding for the project was granted by the Farmers' Home Administration. Construction began in July of 1995 and was completed in early November of 1995.

Scope of Work: Design and development of replacement public-water-supply system.

In 1995, several residences and businesses in the Town of Corinna, Maine, were discovered to have contaminated water supplies. The Town, which had no public drinking-water-supply-and-distribution system, retained Acheron to research the extent and nature of the contamination and design possible remediation. After drinking-water tests were conducted at several residences and businesses in the Town, it was discovered that the contamination was from chlorobenzenes and that it was localized. As a temporary solution, filters were added to the affected wells.

Acheron and the Town decided that a long-range solution would be the design and construction of a drinking-water-supply-and-distribution system. Acheron conducted hydrogeologic studies to locate a suitable well. Acheron then utilized Waterworks, a computer modeling program, to design a pump station and distribution system. The Town decided to limit the system to residences and businesses with contaminated water, but plans to someday expand the system to include the entire Town. Given these present and future plans, Acheron modeled and designed a system that would serve the entire Town and include a fire protection system. Only a small section of the system was initially proposed for construction, but since current construction was limited and future construction was facilitated in the design, the Town saved money currently and will save money in the future.

The initial portion of the system constructed in part, the following components:

a pumping station with a 20,000-gallon finished water-holding tank;
approximately 5,900 L.F. of 8" D.I. waterline; and
approximately 3,000 L.F. of copper service lines.

Monies to fund the project were obtained in large part from a grant/loan package procured through the Rural Economic Community Development (RECD) program. Construction began in July 1995 and the first customers were brought on line in late November of 1995. Representatives of RECD indicated that the Corinna project was presented to their Washington, D.C. headquarters as a model project in terms of cooperation, budget control and system implementation.

Scope of Work: Determine presence, degree, and distribution of petroleum contamination in the bedrock and surficial aquifer, from groundwater, surface water, domestic well sampling and from analysis of surficial and bedrock geologic characteristics.

Acheron performed a full hydrogeologic assessment for a general store site known to have had petroleum release on the site from former underground storage tanks. The project was initiated by collecting samples from the most immediate downgradient private supply wells and the well on the subject property for petroleum/total gasoline laboratory analysis.

This project involved a full evaluation of the nature and extent of suspected soil and groundwater contamination resulting from leaky underground gasoline tanks. The project involved assessment of both the bedrock and surficial aquifer in terms of the potential for contaminant migration within the hydrogeologic system. Installation of bedrock and overburden monitoring wells, field geologic mapping, remote sensing, receptor analysis, domestic well survey, borehole hydraulic conductivity testing, comprehensive soil and water sampling program, and generation of site health and safety and quality control plans.

Based on the hydrogeologic analysis and the analysis of fate and transport characteristics of the identified contaminants, the DEP made a no further action determination and closed the site. The site was characterized as a "Stringent Standards" site.

Technique Summary:
Drilling: Installation of five (5) monitoring well clusters; one (1) overburden well and one (1) bedrock well per set.

Sampling: Neighboring residential wells, monitoring wells, surface water and a downgradient spring along with soil during drilling operations, were sampled and analyzed for hydrocarbon constituents.

Geologic Mapping: Aerial photography and field mapping were performed to evaluate major bedrock lineaments, composition, structure, and strike and dip of bedrock formations.

Receptor Analysis: A domestic well survey was performed that provided data on overburden geology, bedrock geology, well construction, and well yields. Field reconnaissance and evaluation of published maps and reports provided information on proximity of water supplies, significant sand-and-gravel aquifers, springs, sensitive wetlands, and surface water bodies.

Hydrogeologic Analysis: Borehole hydraulic conductivity (K) testing, horizontal and vertical field survey of monitoring wells, water-level measurements, and development of geologic cross sections, and horizontal and vertical flow nets. Analysis of the groundwater flow rate and time of travel in both the bedrock and overburden aquifers. Analysis of the fate and transport characteristic of identified chemical constituents.

Based on the results of a water system evaluation, Acheron assisted the Sandy Point Water Company in filing for project financing through the newly established State Revolving Fund (SRF) of the Maine Drinking Water Program. Since the Water Company is privately-owned, the SRF program placed additional restrictions on the availability of funds and what preliminary work could be completed prior to the project’s listing on the SRF Intended Use Plan (SUP).

Acheron worked closely with the Company to develop project costs and descriptions to get the project listed on the IUP. This occurred in 1999.

Since then, Acheron has been working with the Company to finalize designs and gain DWP approval for the Contract Documents to allow the required work to be completed during the 1999 construction season. The first phase of the work will be the development of a new production well to provide the required flow volumes. The intent will be to install and properly develop a new well in close proximity to the system’s existing well. Once the new well is developed, the existing well will be taken off line.

Concurrent with the new well development, Acheron will solicit bids from local contractors to install new distribution pipes, water meters and other related items. Acheron requested and gained approval from the DWP that the project be bid only to local contractors, in order to minimize project costs for the Company. The small size of the Company limits its ability to finance system upgrades. Acheron has and continues to work with the Company to keep construction and engineering costs to a minimum.

In June 1995, Acheron was requested to perform a preliminary investigation and evaluation of the existing drinking-water system serving residences along Sandy Point in Stockton Springs, Maine. The system was originally constructed to service a few homes and summer cottages on the shores of the Penobscot River. The system now serves numerous year-round homes, and many summer homes. During peak summer periods, customers have complained of low or non-existent water pressure and inadequate water supply. In response to these complaints, Sandy Point Water Company requested Acheron to perform a preliminary examination and evaluation of the system.

Acheron inspected the water-supply system and obtained available information needed to simulate the system through the Water CAD computer model. To improve the accuracy of the computer model, Sandy Point Water Company installed a water meter inside the pump house at the well site and collected water flow data during the period from January through August 1996.

The flow data indicate that during winter months, average daily demand is consistently less than 2,000 gallons per day (gpd) or 1.38 gallons per minute (gpm). During summer weekends, maximum demand on the system increases to approximately 10,000 gpd or 7.0 gpm on a 24-hour basis due to seasonal residents and the Hersey Resort, with peak hourly demand estimated to be two to three (2-3) times the average demand, or 14 to 21 gpm.

Incorporating the meter data into the hydraulic model of the distribution system identified three (3) critical deficiencies in the system:

1. the well capacity and/or the existing pump is inadequate to satisfy system demands during peak periods,

2. the water storage capacity for the system is insufficient to adequately satisfy flow requirements during peak demand periods, and

3. given the configuration of the distribution system with the well source at one end and a large user at the other end, the section of pipeline along Sandy Point Road is limiting the system’s ability to provide additional water during peak-demand periods.

Scope of Work: Design of an interceptor and treatment system for remediation of contaminated groundwater

Since 1988, groundwater monitoring at the Wilton site has detected the presence of perchloroethylene (PCE) and its degradation products. PCE is a chemical commonly used in the dry-cleaning industry. As part of a long-term remedial investigation, Acheron defined the limits of the groundwater contamination and that the plume was moving towards a nearby stream. Acheron was subsequently retained to design a system to remediate the contaminated groundwater.

Acheron evaluated a wide array of available technologies for the groundwater remediation and determined that an interceptor trench could be used to effectively collect nearly all the flow of contaminated groundwater to the stream. A comprehensive hydrogeologic investigation was required to accurately define the site stratigraphy to fully assess the potential effectiveness of an interceptor trench.

Once collected, the contaminated groundwater must be treated to acceptable levels to permit the treated water to be discharged to the nearby stream. An alternatives analysis evaluated the potential use of traditional pump-and-treat technologies, as well as several in-site technologies such as reactive walls. The alternatives analysis determined that the most economical and effective technology for treatment of the collected contaminated groundwater would be a carbon filtration system.

To design the necessary carbon filtration system, Acheron set up and ran a four (4)-month-long laboratory-scale study to define the effectiveness of carbon and determine the necessary design parameters for a full-scale treatment system. The laboratory study included developing isotherms in batch tests and conduct of an extended column study. As part of the laboratory study Acheron proved that the carbon system could remove the various volatile organic compounds to below drinking water standards levels.

Based on the results of the column study, Acheron developed a full-scale design for the groundwater treatment system. The design was submitted to the Maine DEP for review and approval. In May 1999, Acheron received approval from the Maine DEP to proceed with implementing the groundwater interceptor and treatment system for remediation of the site.