Waste characterisation studies are important tools for helping local governments and private companies make decisions on the best solid waste management programs, policies, and technologies to reduce short-lived climate pollutants. Knowing what materials comprise your waste stream will help you establish the right mix of waste diversion and energy programs to make your community more sustainable.
This webinar led by Brent Dieleman of SCS Engineers, a Senior Project Professional with the division of Sustainable Materials Management provides information on how to conduct a waste characterisation study, what data you can expect to obtain from a study, and how it can be used to make solid waste program and policy decisions. Topics of discussion during the webinar include:
We thank Abt Associates on behalf of the US Environmental Protection Agency for the CCAC Waste Initiative for sponsoring the webinar which took place on March 2, 2018, at 2:00 pm CET.
View the webinar by clicking here.
Vapor intrusion (sometimes known as soil gas intrusion or soil vapor intrusion) is a potential environmental risk that can occur at a wide variety of properties, from former industrial facilities, shopping malls, and even residential properties. Knowing how to assess the risk and mitigate potential harm from soil vapor intrusion is critical to reducing health impacts and mitigating financial and other liability from potential exposures.
What is Vapor Intrusion?
Developers and the public understand that soil and water contamination can pose a health hazard, but vapor intrusion is an environmental health risk that can be overlooked. It is a hazard that can result from both heavy industrial operations and small “mom-and-pop” businesses so that it can be an issue both at industrial properties, suburban strip malls, and even residential developments.
Vapor intrusion is the migration of soil or water contamination from below structures into businesses or homes as a vapor. Common vapor intrusion contaminants from small businesses include benzene from gasoline and perchloroethylene (perc) from dry-cleaners, while large industrial facilities may have a wide range of industrial chemical contaminants. Less common vapor intrusion hazards are mercury, polychlorinated biphenyls, and pesticides.
Determining Whether Vapor Intrusion is an Issue
Environmental due diligence is key to determining whether vapor intrusion is a likely issue. An environmental site assessment (ESA) is critical in assessing the potential for vapor intrusion issues and the current state of vapor intrusion based on past site history. A Phase I ESA will review the current and historical use of the property and surrounding properties to determine where and when potential sources of contamination were present. Leaky underground gasoline storage tanks and poor chemical handling practices at dry cleaners lead to chemical contamination that can create vapor intrusion issues, so the “corner” gas station or the strip mall dry cleaner can be the source of vapor intrusion hazards.
Vapor intrusion can also come from groundwater plumes that originate outside the property boundary, so it is important that any assessment looks for potential contamination issues from nearby properties as well as on-site.
When the potential for a vapor intrusion issue exists, a Phase II ESA should be conducted to determine whether there is contamination, the extent and magnitude of the contamination, and whether the contamination poses a significant health risk. In the Phase II ESA, samples of soil and groundwater are collected from the property and analyzed for evidence of contamination.
If contamination is present, results are compared to screening levels established by regulatory agencies or a health risk assessment (HRA) can be prepared. Either of these strategies can potentially be used to demonstrate that health risks are not significant for the property’s current or future use or to determine the level of remediation necessary.
Dealing with Significant Soil Vapor Contamination
If soil vapor intrusion poses a significant health risk, there are ways to mitigate that risk. Mitigation can include removal of the contamination, active mitigation of the contamination source, and protection against indoor air exposure. The approaches are not mutually exclusive, and multiple risk reduction strategies may be used.
The most effective way of reducing soil vapor risk is to remove or treat the soil or water that is the source. This remediation is the most cost-effective for small sources of contamination and when that contamination can be easily accessed. It is often not feasible to remove the source when contamination originates offsite and moves onto the property in a groundwater plume. It may also be more cost-effective to mitigate risk through other means when the source of the vapor intrusion is extensive or difficult to remove.
In active mitigation, soil vapor intrusion is mitigating by reducing contamination at the source. Active systems can include soil vapor extraction, in which vapor is collected and removed; in situ treatment, which uses chemical reagents to transform the contamination into less toxic chemicals; and containment of the contamination source by some form of barrier. Under ideal conditions, these methods have the potential to be highly effective in reducing contamination but monitor treatment for effectiveness and to determine that the resulting contamination levels are acceptable.
It is also possible to mitigate indoor air exposure to soil vapor intrusion. Underground vents, membranes, and seals beneath the foundation and slab depressurization can reduce the flow of soil vapor into a building. This type of passive mitigation leaves the contamination source in place, which may limit future uses for the contaminated property, but it may be more cost-effective than active mitigation, especially in cases where contamination originates off the property. Regulatory agencies typically require that properties mitigating the movement of soil vapor into buildings monitor the ongoing mitigation on a continuous basis with sensors and alarms or periodic resampling.
What You Need to Know
Soil vapor intrusion is a potential environmental liability, but it is manageable. Environmental due diligence can significantly reduce unforeseen costs of vapor intrusion by identifying the issue for proactive management before development, which is always easier and more cost-effective than trying to address a problem after development. It is possible to mitigate health risk from soil vapor intrusion on developed sites. Developers should work with qualified environmental consultants to address vapor intrusion through each stage of the process to adequately minimize risk.
The CCAC Waste Initiative is hosting a webinar on Best Practices for Waste Characterization Studies on March 28, 2018 from 8:00 – 9:00 am ET. The webinar will be led by Brent Dieleman of SCS Engineers, on behalf of the U.S. Environmental Protection Agency.
Webinar Description
A waste characterization study is an important tool for helping local governments and private companies make decisions on the best solid waste management programs, policies, and technologies to reduce short-lived climate pollutants. Knowing what materials comprise your waste stream will help you establish the right mix of waste diversion and energy programs to make your community more sustainable.
This webinar provides information on how to conduct a waste characterization study, what data you can expect to obtain from a study, and how it can be used to make solid waste program and policy decisions. Topics of discussion during the webinar include:
Webinar access:
Join WebEx meeting
Meeting number (access code): 648 518 922
Join by phone
+1-415-655-0002 US Toll
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Thank you to the United Nations Environment, Climate & Clean Air Coalition (CCAC) for sponsoring this valuable event.
Landfill Sites are Finding Second Lives as Real Estate Properties
Innovative projects have sprung up over the years that house retail, apartments, golf courses, conference centers and hotels. Engineers in the solid waste space are applying several structural design techniques that other industries have leveraged for years like building on piles, which has historically been done on marshlands and other unstable ground. They’re also designing floating foundations that allow for movement and making adjustments when differential settlements happen.
Over the years, SCS has designed landfill-related systems for dozens of projects, mainly apartments, business complexes, entertainment complexes, hotels, parks and golf courses. In the past three years,SCS has fielded calls from developers looking into options, resulting in projects moving into the development stages. From small to the largest landfill redevelopment project in the nation , this article gets you started and leads to more information.
Agri-business companies handling large quantities of chemicals and transporting them through all sorts of conditions to different facilities must be prepared for an accidental spill. Accidental spills create environmental problems that can cost your business. However, agri-businesses can control their response to spills and react in ways that limit the environmental impact and help save time and money should a spill occur.
Environmental consultant, Tony Kollasch first discusses, what businesses can do to minimize environmental impacts? He covers the importance of spill response preparedness and REACT; Respond, Evaluate, Alert, Contain, Take.
Read the full article published in Wisconsin Agri-Business News Quarterly.
SCS Engineers periodically prepares Technical Bulletins to highlight items of interest to our clients and friends who have signed up to receive them. Our most recent SCS Bulletin summarizes the new rules which took effect on October 28, 2016, with compliance obligations under the NSPS Subpart XXX rule beginning November 28, 2016. Originally, states and local air jurisdictions were to submit their proposed EG rules by May 30, 2017; however, there have been some delays in this process, which we condense and detail in this Bulletin. SCS will continually update coverage of this Rule on our website.
An essential part of landfills accepting organic matter is the gas collection and control system (GCCS) for controlling odors and landfill gas (LFG) emissions into the environment; the piping network. GCCS design and construction have evolved significantly over the past four decades, from passive venting trench systems to a sophisticated and elaborate piping systems with specialized components for handling LFG, landfill liquids, and condensate flowing through the piping network.
This detailed article discusses best practices and recommendations that GCCS designers keep in mind; careful attention to these details can potentially save landfill operators significant modification costs and inconveniences prior to and during construction of the final covers.
Read the full article published in MSW Magazine.
About the Authors: Ali Khatami, Ph.D., PE, LEP, CGC, is a Project Director and a Vice President of SCS Engineers. Srividhya Viswanathan, PE, is a Senior Project Manager with over 10 years of engineering experience. David Fisher is an SCS National OM&M Compliance Manager with 18 years of environmental experience.
It’s been 10 years since the first Research, Development, and Demonstration (RD&D) Plans were approved allowing liquids to be applied to municipal solid waste landfills in Wisconsin. What have we learned?
Under an approved RD&D Plan, landfill operators can apply liquids other than recirculated leachate to the waste at municipal solid waste landfills. The RD&D Rule was published by US EPA in 2004, and states had the option of adopting the rule and issuing RD&D approvals. Wisconsin was an early adopter, and 13 of the approximately 30 landfill sites in the US with RD&D approvals are in Wisconsin.
This presentation will look at data from the Wisconsin landfills with RD&D Plans. Each site is required to report annually on a very detailed basis. For this presentation we will zoom out and look at the data on an aggregated basis to address big-picture questions. What are the trends in volumes applied for leachate recirculation versus RD&D Liquids? How do these volumes compare with precipitation? What liquid waste streams have been accepted and how have they been applied? How has RD&D liquid application affected landfill gas generation?
We will also provide an update on the regulatory status of the RD&D rule. On May 10, 2016, a final federal rule was published that revised the maximum permit term from 12 years to 21 years; however, WDNR will have to adopt this change in order for it to be available to Wisconsin landfills.
Share these valuable resources directly from the SCS Website.
ReFED, the San Francisco-based nonprofit committed to reducing food waste in the U.S., has released the Food Waste Action Guide for the foodservice and restaurant sectors, which state that there is a 16 million ton opportunity to reduce food waste and to recover the equivalent of 1.5 billion meals per year within the two sectors.
The guide follows the 2016 publication, A Roadmap to Reduce U.S. Food Waste by 20 Percent. Both publications were developed in partnership with the Food Waste Reduction Alliance (FWRA) along with input from more than 80 expert contributors and a number of restaurants across the country, are designed to help industry leaders develop and implement food waste reduction strategies.
They provide best practices and strategies as well as present a set of proven prevention, recovery and recycling solutions to help the foodservice and restaurant sectors prioritize and accelerate waste reduction activities. Food waste reduction is quickly becoming a key element of financial and reputational value for restaurants and foodservice providers.
As some landfill owners have learned the hard way, the co-disposal of construction and demolition (C&D) fines or sulfur-containing industrial wastes in municipal solid waste (MSW) landfills can generate hydrogen sulfide (H2S) gas. H2S emissions are problematic at a landfill as they can cause odor, create worker safety issues, and cause wear or damage to landfill gas (LFG) collection and energy utilization components. Sulfur content in landfill gas can also impact air permitting for a landfill, either in the form of fugitive H2S emissions or sulfur dioxide (SO2) emissions from combustion.
We will discuss the biological, chemical and physical conditions necessary for H2S generation in a landfill. H2S generation can be prevented by knowing which waste types are likely to contain sulfate and testing incoming waste streams when appropriate. We will also discuss the complexities in trying to model and predict H2S generation in MSW landfills. For sites with high H2S concentrations and/or low H2S limits, we will review different H2S treatment technologies in use today.
