There are a wide variety of environmental investigation techniques that may be desired or required for new construction and remodeling.
Each type of assessment has a different purpose and an ideal time frame to help answer questions without stalling the project. Unfortunately, at present, there is no such thing as a “tri-corder,” a device used in the Star Trek television series that determined types of life forms, genetic structure, chemical makeup and a risk assessment when pointed at any area of interest.
Instead, environmental professionals have a dizzying array of devices and techniques that are used for the investigation. It is rarely a simple matter of collecting the test information. Assessment criterion and the equipment used are frequently complicated to the point that specialists may be needed for each of the different types of scans. There are several types of environmental investigations that can be performed and different tools and timing issues that generally apply to new construction or remodeling. Timing can be crucial. If you have the assessment performed at the wrong time, the results might be misleading or invalid. And if it is too early, then it may need to be repeated. If it is performed too late, delays or even deconstruction to affect repairs may be needed.
Long before the construction process begins, various site assessment activities can help guide the design or even hasten the project. A project can be stopped after groundbreaking if prior site assessments required to satisfy the Endangered Species Act, historic preservation or to identify hazardous wastes have not been performed. Other considerations may include geotechnical applications for earthquake faults, expansive clay soils and percolation tests for septic, drainage and water quality if a well is necessary. Existing buildings may need to be assessed for lead, asbestos, PCBs and a variety of hazardous materials depending on how the building has been used. The initial hazardous site assessment is usually called a Phase 1 inspection. It typically consists of a visual inspection, history and a records search to determine the necessity for more in-depth, focused environmental investigations and a sampling known as a Phase 2 assessment.
Construction documents should clearly indicate the environmental goals and requirements for a project. Environmental inclusions for construction projects should be included as a part of the design and planning process and can become major bottlenecks when added as an afterthought or after a realization that they have been neglected. Visual monitoring is frequently the least costly, most effective environmental evaluation technique but requires a well-trained keen observer (filling the roll of Captain Kirk’s “science officer” in Star Trek.) This observer may not know all the answers, but they know where and how to get those answers. The following are some of the environmental conditions and investigation techniques with which this specialist must be familiar.
Asbestos and Lead Inspections
The problems of asbestos and lead are generally associated with remodeling projects, although toys aren’t the only types of imported materials that may be contaminated with lead, asbestos or other hazardous conditions. Contrary to popular belief, the use of asbestos was never formally banned. The exclusion of asbestos has been a voluntary agreement reached by manufacturers.
Even when the use of a hazard is banned, contaminated materials can still work their way into the supply stream. So even with new materials, an evaluation by a knowledgeable and qualified environmental consultant may be needed. Asbestos and lead regulations vary dramatically in different parts of the country and include a maze of federal, state and local requirements, which frequently involve the Environmental Protection Agency (EPA), air quality boards and the Occupational Safety and Health Administration (OSHA). Certification for asbestos inspection and consultation is generally a must. Remodeling projects involving lead and asbestos may require involvement with a certified consultant throughout the project.
Electrical, Electronic and Thermal Evaluations
Environmental evaluations may also be necessary for a variety of performance requirements. A building that is used as a recording studio, medical facility or with sensitive electronic equipment or computers may need evaluations for electromagnetic interference. Pre-evaluation of the site is important. This will help facilitate identification of problems early so that they can be corrected with little interruption in construction progress is important. Evaluation should include the following:
- Appropriate design considerations
- Measurements of the electromagnetic field and radio frequency after the power system is able to be placed under load but prior to finishing work
- Safety covers
Another important evaluation technique at this point is the use of thermography. When an electrical load is placed on an electrical circuit, many wiring problems can be identified by thermal imaging due to the heat generated.
Thermal imaging is also useful as a diagnostic technique when checking for energy conservation compliance. A knowledgeable thermographer can pinpoint where insulation has been omitted or air infiltration paths are causing energy loss from the building envelope after wall surface claddings have been installed. Of course, these problems are best avoided by careful quality control during the installation process; however, if sub-contactors know their work is going to be performance-checked, there is a better chance they will perform to specification. Other uses for thermal imaging include looking for water leaks in membrane roof systems, energy leakage from the HVAC system and ducts, water intrusions and wet building materials.
As the desire for “green” construction grows, the various completion and compliance evaluations are becoming more popular. The Leadership in Energy and Environmental Design program (LEED) from the U.S. Green Building Council has the ability to gain points for indoor air quality as one part of its criterion. But whether aiming for certification or specification, compliance considerations regarding radon gas, formaldehyde, various volatile organic compounds, combustion by-products, pesticide residues and fresh air ventilation rates can all be evaluated. An increasing array of electronic sensors are becoming available that can be incorporated into HVAC system controls to provide ongoing monitoring and control of the indoor environment. A short-term or “grab” sample is frequently used for initial compliance, but when long-term concerns like radon or combustion by-products can fluctuate within a building, an automated system connected to the Internet through a dedicated phone line can provide the ability to recognize and respond to ongoing issues before they can cause harm.
A major area for environmental investigations involves moisture and mold problems in buildings. These investigations are specialized and generally require a lot more than just an ability to operate a sampling pump. Since mold problems are always associated with water problems, an understanding of the interactions between building materials and moisture is essential. It used to be thought that wood moisture content below 19 percent was sufficient to prevent fungal growth. This level can prevent dry-rot, but a wide variety of surface molds are able to grow on materials such as gypsum, wall board or carpet backing when they are in contact with wood at levels as low as 16 percent. Different materials require different types of moisture measurements in order to assess their true level of moisture and to determine if levels are low enough for sensitive materials to be installed. The depth of measurement is also an important consideration. Many of today’s commonly available moisture meters do not penetrate more than about half an inch. An understanding of equipment limitations is just as important as equipment capabilities.
Demanding careful preoccupancy evaluations and project quality control can help avoid the final type of environmental investigation or at least can lead to results that are favorable for the contractor. This is the post-construction environmental complaint.
Sometimes, these issues are easy to resolve. I was called to investigate a relatively new building because a worker was complaining of severe headaches from “strong chemical smells.” The builder was convinced the worker was crazy, since he couldn’t smell the problem. I first looked at the heating, ventilating and air conditioning system on the roof. My inspection showed that the fresh air supply was completely closed. The building was not getting any fresh air ventilation. The builder consulted with the sub who installed the unit and opened the supply to satisfy The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) standards for fresh air ventilation rates. The problem was solved based strictly on my environmental investigation without any sampling being necessary.
Two weeks later, I received a call that the complaints had started again. I rushed back to the building with air sampling equipment to try to track down the problem. I set up the equipment and let it start collecting the air for an analysis of volatile organic compounds. While it was sampling, I decided to go back on the roof to look at the HVAC system again. The fresh air ventilation was once again completely closed. It turned out the company that was responsible for changing filters had been there the day before, changed the filters and closed the fresh air supply again to “save energy.” The complaining employee wasn’t crazy. Reopening the ventilation supply to the recommended level of fresh air once again inexpensively solved the problem. This illustrates that indoor air quality depends on much more than the construction of the building.
Every construction project should have an experienced “science officer” advising the “captain,” or construction business owner, from the beginning of the project. This person can help limit liability and provide the quality control necessary for steering the project to a successful conclusion through the myriad of regulatory compliance and specified environmental requirements for a project.
John Banta is certified by the American Board of Industrial Hygiene as an Associate Industrial Hygienist and specializes in indoor environmental quality in problem buildings. Banta performs environmental investigations, teaches classes and can be reached at 916.736.1100 or www.restcon.com.
Construction Business Owner, March 2008