Sub Slab Depressurization Systems

This year's hot topic with respect to waste site clean up is undoubtedly Vapor Intrusion.  Regulators, property owners, licensed site professionals and other stakeholders are paying significant attention to volatile organic compound (VOC) migration into indoor air.  This attention may be warranted given the potential human health risk - we now better understand that volatiles in indoor air are a health concern.  However, the fix for the problem is not terribly complicated and, from a technical perspective, is the same fix to address radon.  We have been solving radon problems for decades.

Several years back radon was discovered in new and existing homes at unacceptable levels.  The most cost effective solution was the installation and operation of a sub slab depressurization system (SSDS), which captured the radon vapors from beneath the home and discharged the contaminant to the outdoors well above the roofline.  These systems were designed to prevent the vapors from migrating into the home.  Collecting the naturally occurring radon before it entered the home and discharging radon to the atmosphere is much less expensive and much more effective than attempting to treat contaminated indoor air.

This same SSDS technology is being used today, with endorsement from the Massachusetts Department of Environmental Protection (MADEP), to mitigate potential VOC migration into buildings.  The system typically consists of either vertical or horizontal PVC extraction wells installed beneath and through the floor connected to a small fan which exerts just enough negative pressure under the building to prevent migration of vapors into the building through tiny cracks or holes in the floor. Most often, vapor migration is further prevented through the installation of a physical barrier (e.g., liner) between the subsurface and the living space.  The system is not designed to actively treat or remove the VOCs from the environment, such as with a more powerful soil vapor extraction (SVE) system, rather the SSDS simply collects and redirects the vapors thereby preventing vapor intrusion.

Several of the same companies, like GEC,  that can address the radon problem are now installing virtually the same system to mitigate the VOC intrusion issue today.  SSDSs are being installed in existing buildings where contamination is newly discovered, and are installed in new construction as a preventative measure.

GEC has installed SSDSs with great success and anticipates the trend to continue as more information becomes available about the health risks of VOC intrusion.

Draft Guidance on Implementing Activity and Use Limitations

In December 2010, MADEP issued a public comment draft of the Guidance on Implementing Activity and Use Limitations (Policy #WSC-11-300) ("Guidance").  The intent of the Guidance is to provide assistance to parties preparing and implementing Activity and Use Limitations (AULs).

This public comment draft is an update to the existing Guidance first developed in 1999, and is needed because there have been revisions to the Massachusetts Contingency Plan (MCP), associated policies and guidance, and the Registry of Deeds formatting requirements.  The draft Guidance also provides clarification on those issues most commonly resulting in violations of the MCP and addresses frequent questions by stakeholders.  It also provides more reference tables and checklists to provide greater certainty that the AULs are prepared and filed properly.

Overall, the proposed changes to the Guidance are beneficial and provide better direction on the AUL preparation and filing process.  There are a few issues that warrant special mention here.  First, for AUL areas where protective barriers are needed to avoid direct contact of soils, the MADEP wants a Plan of Land or survey plan showing the location of each type of protective barrier (e.g., concrete, pavement, building foundation, walkway, or a landscaped area over a protective membrane, etc.).  If retained as drafted, this requirement would mean that every time a protective barrier is changed, the AUL and / or Plan of Land registered at the Land Court or recorded at the Registry of Deeds would have to be updated.  Therefore, to save money, prior to filing the AUL, careful consideration should be given as to what types of protective barriers are desired within an AUL area over the long-term.  Currently, a survey usually is conducted only when an AUL is implemented on a portion of the property.  Under the Guidance, a survey will always need to be conducted when filing an AUL, resulting in an increase in cost of AUL preparation.

Second, the draft Guidance provides some information on AULs and the use of sub-slab depressurization systems to eliminate the intrusion of vapor from contaminated groundwater.  AULs and elimination of the vapor intrusion pathway is also addressed in the draft Vapor Intrusion Guidance document, for which the public comment period recently closed.  GEC believes the Guidance on Implementing Activity and Use Limitations should not be finalized until after the comments on the Vapor Intrusion Guidance are considered.  Refer to GEC's Newsletter, dated January 19, 2011 for an earlier article on AULs and the Vapor Intrusion Guidance.

Third, the draft Guidance requires gardening of edible produce/flowers be considered a current use for residences.  An AUL can not be used to eliminate a current use.  However, the Guidance does not recognize differences between types of residential properties.  There is a significant difference between a single-family residential lot and a large apartment / condo complex.  The AUL process should recognize the difference between different types of residential properties and allow the use of more institutional controls for larger residential complexes.

The due date for providing comments on the draft Guidance to the MADEP is May 1, 2011.

Supply Chain Evolution

Concerns about the business value of sustainability initiatives are reminiscent of where we were when the environmental movement started.  In the late '60s and early '70s, many businesses developed extensive rationales as to why efforts and expenditures on environmental concerns like clean air and clean water were not part of a company's priorities.  There was no specific corporate responsibility to these "public goods" or any social contract.  The responsibility of the corporation was solely to its shareholders and that responsibility was primarily to provide sufficient return on their investment.

Fast forward 40 years, substitute "sustainability" for "environment" and the arguments have changed little.

We have previously written about GE, IBM and WalMart as proponents of corporate sustainability and supply chain requirements.  They are not the only ones.  Several hundred major companies including Ford, Dell and Proctor & Gamble (P&G) have similar programs and requirements.  The message from these companies appears clear: We are willing to help you continue as our supplier, but only if you commit to helping us meet our goals and some of those goals go well beyond environmental compliance efforts. 

P&G recently issued a press release entitled P&G First Year Supplier Sustainability Scorecard Results in Collaboration and Innovation.  In this press release P&G's message to suppliers is: "P&G improves the environmental quality of our operations and our products. We strive to do business with suppliers who share our concerns for and commitment to preserving the environment." 

As detailed in the release, P&G initiated their "scorecard" to measure and improve the environmental performance of the Company's key suppliers and business partners with three expressed goals:

1. Enhance supply chain collaboration;
2. Improve key environmental indicators; and
3. Encourage the sharing of ideas and capabilities to deliver more sustainable products and services for our consumers.

The P&G Supplier scorecard assesses the total environmental footprint of external business partners and encourages continued improvement by measuring energy use, water use, waste disposal, and greenhouse gas emissions on a year-by-year basis.  This tool is sufficiently flexible and user-friendly, so any supplier from manufacturing to advertising can track key indicators in a way that works for them and P&G.  In this way, the scorecard drives collaboration and creates opportunities for innovation.  P&G, and the other companies mentioned, are encouraging a collaborative effort, but the underlying message of the scorecard is: "If you cannot or will not improve, then we will find another supplier."

According to the press release, their scorecard system has now been in place for over a year.  The scorecard asks suppliers about their resource use and emissions, and also seeks ideas related to sustainability.  The initial scorecard was sent to 383 of P&G's biggest suppliers and intended to make sure the company could get clear data and feedback.

With over 300 companies responding and many reporting on energy use, direct and indirect emissions, and waste, P&G says it will send out an updated version to around 600 suppliers and for the first time use the scores to calculate suppliers' ratings, which are also influenced by costs, quality and other factors.  Suppliers get scored based on their year-by-year results, and P&G will publicly reward "exceptional performance," according to Chief Purchasing Officer Rick Hughes. Rewards will also go to those that bring in innovative ideas.  When suppliers score poorly, P&G will develop improvement plans to get them on track.  If they won't get with the program, they will be dropped.

Out of the suppliers that completed the scorecard, 94% reported on their energy use, and the metric that the fewest (63%) reported on was Scope 2 greenhouse gas emissions.  Almost 40% also submitted sustainability-related ideas and input.  P&G is all for these suppliers getting on board and encourages them to get the help they need.  They are looking for accuracy and integrity, and help in improving P&G's own scorecard.

What does P&G gain? They say: "The growing expectation of our consumers, customers and stakeholders is a further catalyst to extend this practice throughout our supply chain."  It is a long-term attitude that positions P&G to hold on to customers, while responding to consumers and stakeholders.  It shifts "environmental" from being a "cost center" to being a key "profit center" in their strategic planning process.

Pushing sustainability down the supply chain and sharing information with suppliers will also help P&G achieve its own environmental goals, such as its plan to eventually use 100% renewable or recycled material in all products and packaging, something possible only with materials and packaging providers on board.

GEC has maintained that whether you call it a scorecard or something else, the deliberate iterative process of plan, do, check, act implicit in the environmental management system results in improved environmental compliance and improved performance.  Acquisition and consideration of environmental performance metrics will lead to cost savings, liability avoidance and accident prevention.  In a real sense, this is an opportunity for growth, if you can position your company to take advantage of it.  If you sense that you company's future will be dependent on your customer's procurement requirement, GEC can enhance your agility and help you develop the programs and procedures that will assure continued success.