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2011 Maine Water Conference
Wednesday, March 16, 2011
Augusta Civic Center, Augusta, Maine
SESSION 4
Green Remediation - Practical Considerations
Chair: W. David McCaskill, P.E., Senior Environmental Engineer, Division of Technical Services, Bureau of Remediation and Waste Management, Maine Department of Environmental Protection
Chair Bio:
David McCaskill has been with the Maine Department of Environmental Protection since 1986, except for a brief stint working for an environmental consultant in the early 1990’s. David is a Senior Environmental Engineer and as Unit Leader of the Bureau of Remediation and Waste Management (BRWM) Technical Assistance/ Oil Spill Prevention Unit he is responsible for the state Spill Prevention Control and Countermeasure (SPCC) and Home Heating Oil Tank Replacement programs. He also serves as a resource to the Department for developing strategies to target and implement new tank and equipment technologies for use in Maine for both the Underground Storage Tank (UST) and Aboveground Storage Tank (AST) programs. In the last couple of years he has been tasked with tank removals and soil remediation at abandoned UST motor fuel facilities throughout the state targeting locations that threaten groundwater resources. He serves as the co-chairman of the Maine DEP/Consulting Professionals of Maine Taskforce and as BRWM representative on the Pollution Prevention/ Compliance Advisory Panel. He is also a regular contributor to LUSTline, a national quarterly bulletin on underground storage tanks/leaking underground storage tanks (UST/LUST) issues published by the New England Interstate Water Pollution Control Commission. David holds a BS in Civil Engineering from Mississippi State University and is a licensed Professional Engineer in Maine.
Description: A few years ago, US EPA and state waste management officials introduced the term "Green Remediation" with respect to petroleum and hazardous waste soil, and groundwater site clean-ups. What does this mean and can it be done on a practical level here in Maine? The concepts range from "whole-site" approach to specific on-site or near site remediation efforts to reduce the high carbon appetite of traditional off-site "muck and truck" soil removal. The purpose of this session is to highlight recent "greenish" remediation projects and to explore some practical thinking on what can be done in the future here in Maine.
AM Session
From landfill to best management practice, a beneficial re-use application of water treatment residuals
Bjorn Lake1, Jim Hart2, Aria Amirbahman1
1
Civil & Environmental Engineering, University of Maine, Orono, ME
2
Kennebec Water District, Vassalboro, ME
The Kennebec Water District (KWD) is a quasi-municipal public drinking water utility serving a population of 22,500 in central Maine. The KWD draws their water from the China Lake Watershed (Kennebec County, Towns of Vassalboro & China) which is listed as 303(d) impaired waterbody. As part of the water treatment process, aluminum sulfate coagulants are used to clarify the influent. The resulting water treatment residual (WTR) is collected in a recycle lagoon and dewatered before being landfilled. This process is economically costly to the KWD and their customers as well as unsustainable with respect to solid waste management. As an alternative to landfilling, beneficial re-use applications of the WTR have been researched including wastewater treatment, construction material production, and soil amendments. In this pilot study, we characterized the physical and chemical parameters of the WTR produced at the KWD to investigate its use as a sorptive media for phosphorus immobilization in septic leach fields. We determined the hydraulic conductivity, particle size, phosphorus sorption isotherms, and the advection/dispersion characteristics to properly derive design parameters. The Maine Lakes Resource Center opening in Belgrade, ME, will be the site of the first field experiment using WTR in a septic leach field in the spring of 2011. This field experiment will be discussed along with other possible WTR re-use applications across Maine.
Bio-pile siting, construction, operation, maintenance, and application on petroleum contaminated sites. Rangeley and Gardiner, Maine bio-pile examples.
Nicholas O. Sabatine1, P.G., Erik P. Phenix1, C.G., John K. Cressey2, John B. Rand3
1 Ransom Environmental Consultants, Inc., Portland, Maine
2 Summit Environmental Consultants, Inc., Augusta, Maine
3
JBR Consulting Hydrogeologist, Raymond, Maine
Ransom Environmental Consultant, Inc. (Ransom) and Summit Environmental Consultants, Inc. (Summit) have been engaged through the Maine Department of Environmental Protection (MEDEP) Brownfield Program to site and construct bio-piles at sites in Gardiner and Rangeley, Maine respectively. Bio-piles are a remediation alternative that can significantly reduce costs associated with petroleum contaminated soil management and disposal, while successfully reducing contaminant concentrations and allowing the soil to be made available for beneficial reuse options. Unlike traditional “land farming/land spreading” operations, the example bio-piles were designed to be self-sufficient. Through the augmentation of soil nutrients, active circulation of air, and optimization of ambient heat, petroleum hydrocarbons are degraded without the need for regular labor or mechanical maintenance.
Numerous factors, including siting constraints, contaminant characteristics and concentrations, soil chemistry, end use objectives, and mechanical and coordination logistics, need to be considered in the design and construction of a bio-pile. Each of these considerations will be discussed in relation to the example bio-piles, as well as suggestions and recommendations for future bio-pile projects.
The Rangeley bio-pile project will be presented as a case study in low-maintenance bio-pile remediation. The Rangeley project involved the evaluation of three separate bio-pile designs. One pile was used as a control, and received nutrient augmentation only. A second pile was designed with a re-circulating air system in addition to nutrient augmentation. The third pile included a solar collector connected to the re-circulating air system, along with nutrient augmentation. Findings from the Rangeley bio-pile project will be discussed in terms of temperature, nutrient depletion, microbial activity levels, length of treatment season, and percent reduction in contaminants.
An Emerging Contaminant – 1,4-Dioxane: Transport, Fate and Treatment at a New England Superfund Site
Charles A. Crocetti, Timothy M. White, Scott R. Nerney
Sanborn, Head & Associates, Inc., Concord NH
We will present and discuss apparent differential transport of 1,4-dioxane and other volatile organic compounds detected at the site. Based on observations from this site, and its physical/chemical properties, 1,4-dioxane may commonly be found at the leading edge of chlorinated solvent groundwater plumes. Historically, 1,4-dioxane was used as a stabilizer for 1,1,1-trichloroethane and trichloroethene, both principal contaminants at this site. Chlorinated VOC-contaminated groundwater has migrated off-site contaminating several private water supply wells, both bedrock and overburden. Municipal water is not available in the area.
1,4-dioxane concentrations of up to 80 ug/l have been found at the downgradient limits of the plume, while in known contaminant source areas the concentrations remaining after 20 years or more are typically about 1 to 10 ug/l. This pattern is substantially different from the chlorinated and aromatic VOCs. The observed 1,4-dioxane distribution is thought to be due to its high solubility and greater partitioning into groundwater at NAPL source areas, and resistance to adsorption, biodegradation and other attenuation mechanisms, relative to other VOCs.
We will also discuss the observed performance of point of entry treatment systems installed at supply wells, consisting of granular activated carbon, which have been more effective than initially anticipated at removing 1,4-dioxane, which has a relatively low affinity for carbon (low Koc).
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