Case Studies
Difficult Problems. Unexpected Sources. Practical Solutions.
A mold test can miss mold hidden inside a wall. A flood that assumed to cause a mold problem may have created a chemical problem instead. An odor can originate and travel through an unexpected pathway. Laboratory resultw can be wrong. Sometimes the source everyone is worried about isn't actually the problem.
For more than 25 years, I've investigated mold, moisture, indoor air quality, VOCs, odors, electromagnetic fields, construction problems and unusual environmental conditions in homes, commercial buildings and institutional facilities. The cases below aren't organized by what I tested for.
They're organized by the problem that had to be solved.
Nobody Could Find the Source
A Gas Leak No One Could Find for More Than Two Years
Hotel spa | Gas leak and unexpected building pathway
Employees in a hotel spa had intermittently complained about feeling sick, and reported a concern about a gas-like odor or more than two years.
The gas utility had been called twice and had been unable to locate a leak. I was able to locate the source using odor and targeted gas detection.
The surprising part was how the gas was getting into the building. The main electrical service and gas piping entered the building through the same utility trench. A leqk in the gas main outside the building was able to enter the electrical conduit and entered the building through an electrical outlet on an exterior wall.
The problem confirmation that the concern about a gas-like smell was real, and then locating where and how the gas was entering the building.
No One Could Find Where
The Fire-Suppression System Was Leaking.
Government building | VOC investigation
A large government building had a suspected environmental problem involving its fire-suppression system. VOC testing didn't reveal much of significance, with one exception. I detected a refrigerant-type compound associated with the fire-suppression system.
I attempted to pinpoint the leak using a refrigerant detector. The manufacturer's technician couldn't find it. I tested the building again to verify the chemical signature was still there. The repeated VOC finding continued to point to the fire-suppression system.
My recommendation was: if the manufacturer's technician could locate and repair the leak, repair it. If the system continued leaking and the source couldn't be located, replace it. Sometimes solving a problem requires answering the questions necessary to decide what to do next.
The Suspected Problem Wasn't the Problem
They Thought the Flood Had Caused Mold. It Was Something Else.
Ski resort | Flooding, odor and VOC investigation
Rapid spring warming melted a large amount of remaining snow and flooded ground-level staff offices at a ski resort. Employees subsequently reported symptoms. I was hired to investigate for mold.
I didn't find much mold, and the offices didn't smell like mold to me. They smelled like mothballs.
I collected a VOC sample to investigate what I was smelling. The concentrations of compounds associated with mothballs were elevated. That was a mystery: Why would there be mothballs in staff offices at a ski resort?
When I presented my findings, employees supplied the missing piece. Mothballs had been placed around the perimeter of the rooms and in corners in an effort to deter mice and other rodents. The floodwater had contacted the mothballs and distributed the chemicals into the carpet and lower portions of the walls.
The solution wasn't conventional mold remediation. I recommended removing the contaminated carpet and the lower two feet of affected drywall.
The flood was real. The employee complaints were real. The assumption that mold explained the problem was wrong.
The School Was Worried About a Cell Tower.
The Higher RF Levels Were Actually Inside.
School | RF and cellular-tower investigation
A school hired me to assess radiofrequency exposure from a nearby cellular tower. I measured the RF environment outside the school. Then went inside. The readings increased. Using a Narda instrument configured to differentiate frequency ranges and sources, I investigated what was contributing to the indoor measurements.
The higher indoor levels were associated with sources within the building - personal cellular phones, Wi-Fi, Bluetooth and other wireless sources. One of the simplest observations was one of the most useful: stepping outside the building in the direction of the cellular tower caused the measured level to decrease.
The school had hired me because it was worried about the tower. Once the measurements showed what was actually happening, the concern immedietely ended.
Sometimes the solution isn't remediation. It's finding out that the thing you're worried about isn't a problem.
When the Test Didn't Answer the Question
The Nose That Knows: Finding Mold a Normal Air Test Missed
Residential home | Hidden mold and wall-cavity investigation
A freshly painted home was for sale. It looked good, and previous mold air testing had produced good results. My client wanted a second opinion. Rather than simply repeating the same air testing, I went looking for evidence of a hidden problem.
Odor is one of the tools I use during an investigation. Electrical outlets can be useful as they're openings into wall cavities. I found an outlet where the air from inside the wall smelled like mold.That helped me isolate several suspect walls.
I tested the wall cavities and found the mold that hadn't been identified by the previous testing.
The seller's agent wasn't happy to see me when the investigation began. By the end, the problem had been identified, the transaction was able to move forward, and the agent gave me a nickname:
“The nose that knows.”
When Laboratory Results Are Wrong
Residential mold investigation | PCR testing and laboratory QA
Another mold inspector's PCR testing indicated a significant mold problem. The problem was that I couldn't find physical evidence consistent with what the laboratory results appeared to show. Instead of assuming that a sophisticated laboratory method had to be correct, I investigated the discrepancy.
Comparisons with other testing didn't agree with the anomalous results. Subsequent communication with the laboratory uncovered significant quality-control problems, including a reporting/data-entry error and an incorrectly configured calibrator that substantially affected calculated results.
The issue wasn't whether PCR technology can detect fungal DNA.
The useful question was:
When a laboratory result conflicts with the building investigation and other evidence, why doesn't the evidence agree?
When Remediation Didn't Solve the Problem
The Asbestos Was Removed. The Mold Was Painted Over.
Shopping mall | Mold, asbestos and failed remediation
A shopping mall had a mold problem. During the investigation, I also identified asbestos-containing materials.
That changed how the work needed to be performed. I recommended using a contractor qualified to perform the asbestos removal. The asbestos-containing materials were removed. Portions of the mold-affected materials were coated with shellac rather than physically removed.
The asbestos problem had been addressed. The mold remediation had not.
Once the asbestos-containing material was gone, there was no reason to continue relying on the asbestos contractor for the remaining mold work. I trained the owner's existing building contractor to remove the remaining mold-affected materials under appropriate containment.
The solution was both more effective and less expensive. The owner obtained a refund for the deficient portion of the original mold remediation. Sometimes the answer to failed remediation isn't more remediation. It's determining why the first attempt didn't solve the problem.
When the Source Was Somewhere Unexpected
The VOC Source Was Under the House
New green home | Sub-slab insulation and VOCs
While testing the indoor air of a newly constructed green home, I detected an unusual refrigerant-type compound. Its presence was interesting because the compound was associated with the blowing agent used in a particular type of rigid foam insulation. The builder helped complete the picture: that particular insulation had been used in only one location in the house: under the concrete slab.
That meant the source wasn't in the occupied space. The evidence pointed toward migration into the house through a pathway analogous to other sub-slab gases such as Radon. Removing insulation beneath a finished concrete slab wasn't a practical solution. I recommended installing an energy-recovery ventilator to provide continuous ventilation and reduce the compound indoors.
Finding the source and determining what to do about it are sometimes two different problems.
Why Did a House Smell Like Roofing Materials When It Got Hot?
Residential home | Roofing materials, odors and VOC source comparison
A homeowner reported a roofing-like odor indoors after installation of a new roof. The odor became particularly noticeable as the roof heated during the afternoon. The investigation required more than simply measuring total VOCs.
I collected indoor-air samples and samples of components of the roofing assembly so their chemical profiles could be compared. The indoor air contained a substantial petroleum-hydrocarbon pattern. Testing of the roofing materials identified overlapping compounds consistent with contributions from components of the roofing assembly.
The evidence supported the roofing assembly as a source affecting the indoor environment, while not establishing that a single roofing component was exclusively responsible.
My recommendation therefore addressed the affected assembly, rather than pretending the available evidence could assign every indoor compound to one particular layer. This case demonstrates an important distinction:
You don't need to claim more than the evidence establishes in order to solve the problem.
When the First Solution Didn't Work
The New Green Home Failed Its Indoor Air Quality Test—Twice
Panasonic | New construction, ventilation and VOC source control
Panasonic hired me to independently evaluate indoor air quality in a newly constructed green home equipped with one of its energy-recovery ventilators.
The house failed my testing.
The first investigation identified problems with how the ventilation system had been installed and operated. The ducting had been installed incorrectly, and the ventilation had been programmed to operate only part of the time based on a square-footage calculation.
I recommended correcting the installation and operating the ventilation continuously.
We tested again.
The house failed again.
This time, the VOC profile provided the clue. A significant portion of the compounds was associated with gasoline.
The homeowner collected race cars in the attached garage. I recommended dedicated continuous exhaust ventilation for the garage, creating a slight negative pressure relative to the house and reducing migration of garage contaminants into the living space. After addressing the second problem did the home achieve the indoor-air-quality results we were looking for.
Panasonic subsequently published the project as a case study, reporting total VOC concentrations decreasing from approximately 7,600 ng/L to 610 ng/L—a 92% reduction.
The lesson wasn't simply that ventilation works.
The first solution didn't work. Find out why. The second test revealed a different problem. We then solved them both.
When You Need to Know Which Exposure Matters
A Pacemaker in a Power Plant
University of New Mexico | EMF characterization
The University of New Mexico asked me to evaluate its power-plant facility after an employee received a pacemaker. The question wasn't simply, “Are there EMFs here?” Of course there were. It was a power plant. The question was which electromagnetic fields and locations were relevant to the operating specifications of the Medtronics pacemaker installed.
I characterized the facility for the field types and frequencies addressed by the pacemaker manufacturer's specifications, including electric and magnetic fields, AC and DC fields, and radio frequencies. The significant finding was localized 60-Hz AC magnetic fields around large pumps. That allowed particular locations to be designated as areas the employee should avoid rather than unnecessarily restricting access to the entire facility.
The relevant exposure was isolated to a particular type of field. An AC magnetic-field gauss meter was provided to the employee so unfamiliar environments could be evaluated as needed.
The objective wasn't to measure everything and hand someone numbers. It was to determine which measurements mattered to the problem.
Three Teachers With Brain Cancer: What Did Their Offices Have in Common?
School | Environmental investigation and magnetic fields
Three teachers who had developed brain cancer had offices clustered in the same area of a school. I investigated a broad range of potential environmental conditions. Mold, VOCs, radon, particulates and the other conventional indoor environmental parameters were normal. The indoor-air-quality findings were actually quite good.
One environmental condition stood out: elevated 60-Hz magnetic fields.
I traced the fields to unbalanced current on the electrical feeder serving the building. The electrical/service area was located centrally relative to the affected offices. I was able to trace the magnetic-field pattern along the feeder route beneath classroom floors.
The investigation identified an unusual environmental condition, found its source and provided a condition that could be corrected rather than leaving an unnecessary exposure in place.
When the Accepted Rule Didn't Answer the Question
Does 1% Char Mean a Home Was Contaminated by a Wildfire?
Insurance investigation | Wildfire claims and forensic dust analysis
Following major wildfires, an insurance company asked me to investigate approximately a dozen residential claims where the adjuster questioned whether the homes had actually been significantly affected. In addition to conventional observations and wipe testing, I collected settled-dust samples for analysis using multiple microscopy methods, including scanning electron microscopy.
At the time, a commonly used interpretation was essentially: More than 1% char = wildfire contamination. I questioned whether that percentage actually established the source. Char isn't unique to wildfires. Fireplaces, wood-burning appliances, BBQ grills and other ordinary combustion sources can contribute combustion particles to residential dust.
I collected background samples around those kinds of sources. The results led me to conclude that a 1% char threshold by itself wasn't sufficient to establish that a home had been contaminated by the wildfire.
The better question was:
What's actually in the dust, what are plausible sources, and does the evidence establish that this house was affected by this wildfire?
The investigation did not support significant wildfire contamination in the homes evaluated, consistent with the adjuster's initial observations.
What These Cases Have in Common
The technical subjects are very different. Mold. Gas. VOCs. Roofing materials. Fire-suppression systems. Wildfire particles. Ventilation. Electrical fields. Radiofrequency sources. The problems are similar. Someone has an observation, a complaint, a test result or a theory about what's happening. I ask:
What do we actually know?
What's unusual?
Where is it coming from?
Does the testing answer the question we think it answers?
What evidence doesn't fit?
What needs to change to solve the problem?
That may mean finding something previous testing missed. It means questioning a laboratory result, tracing a contaminant through an unexpected building pathway. It may be discovering that the thing everyone thought was the problem wasn't the problem. Sometimes the most useful result is finding that nothing needs to be done about the thing you were worried about.
Have a Problem That Hasn't Been Solved?
If you've had inspections, testing, remediation or contractor evaluations and still don't know what's happening, or your problem doesn't fit the usual categories, tell me what's going on. I take on selected residential, commercial and institutional investigations, including projects that require travel.