1. Tri-Tech Building Hygiene Services
Is Less Always More?
Two Case Studies in Building Management Grouping (BMG) for
Lead-Based Paint Inspections
For multi-family housing testing for lead-based paint (LBP), the HUD protocol prescribes
a statistical random sampling of units based on a published schedule. This sampling
method requires units of similar painting and maintenance history to be grouped together.
The sampled units are used to project the LBP present in the untested units. It is common
for lead paint testing firms to competitively bid on doing the bare minimum required
units, treating all the units the same. Building owners are often reluctant to disclose
knowledge of atypical units during bidding, correctly believing it will increase their
testing costs. While the building owners may wish to do the bare minimum to minimize
costly lead paint testing fees, they should be warned of the long-term disadvantages, as
these two case studies illustrate below:
Apartment Complex constructed in 1968
Tri-Tech was retained to perform a Lead-Based Paint Inspection and Risk Assessment of
a two-story two-building apartment complex constructed in the 1968. The building
contained a total of 110 units subjected to lead clearance testing. Based on the age, a
minimum of 26 units is required to be tested for LBP. The owner had only owned the
building for about one year and did not have good historical information about the
painting and maintenance history but believed all the units were similar. However, after
random selection of the units was performed and the inspection was started, it was
learned from on-site personnel that two units had been nearly gutted and re-drywalled
due to a leak from an adjacent boiler, which had caused flooding and severe mold impact.
These units were not scheduled to have been tested. By setting aside these units and
testing them separately for the remaining original painted components, Tri-Tech was able
to identify these as lead-free units that would have otherwise been projected to contain
LBP based on the results of the typical unit testing.
In addition, one unit was inspected and found to be dissimilar. The carpet was heavily
stained and had not been replaced in many years and much more LBP was found on the
living space walls, unlike the other atypical units. It was inferred that this was the on-site
residence for maintenance or management personnel and was painted separately from the
normal tenant turnover painting program. By setting this unit aside as a separate BMG,
the owner obtained the benefit of not having this anomalous unit cause the remaining 82
untested units to be managed as having LBP in the Living Room, Dining Room, Master
Bedroom or Hall. It should be noted that one anomalous unit does not necessarily affect
the determination for untested units, but in this case there were already a few additional
anomalous and apparently random occurrences from LBP that, combined with this
finding, would have made a substantial difference in the LBP determination.

2. Tri-Tech Building Hygiene Services
Apartment Building constructed in 1921
Tri-Tech was retained to perform a Lead-Based Paint (LBP) Inspection and Risk
Assessment of a four-story apartment complex constructed in the 1921. The building
contained a total of 91 units. Of these, 75 contained bedrooms and were subjected to lead
clearance testing. The owner reported that all of the units had a generally similar painting
and maintenance history except that one unit had newer vinyl windows but had only
owned the building for about 10 years. The City Building Department incorrectly
reported the building age as 1955 and this was thought to be a possible date of major
renovation. The specific renovation history of the rental units was unknown. Based on the
age of the building, it was judged likely that some wall/ceiling replacement and unit
reconfiguration had occurred. Since it is not uncommon for a few units to be damaged
and gutted due to water, fire or vandalism damage over time, is the practice of Tri-Tech
to have an allowance budgeted for the discovery of atypical units that may not have been
known to the Owner but would be recognizable to an experienced building inspector.
Tri-Tech proceeded with the lead testing of the minimum prescribed 39 of the 75 total
units. During unit testing activities, it was discovered that the two northernmost wings on
the Fourth Floor were dissimilar from the other units. These units were characterized as
different from the others by the presence of LBP on the Kitchen walls and ceilings and
the interior (non-window) walls and ceilings of the Bathroom and LBP on baseboard in
the Master Bedroom. LBP was not found to occur at these locations in the other typical
units. The LBP was also generally less intact than the other typical units. It appeared that
these two wings were omitted from renovation at one point or were otherwise managed
differently. Therefore, these atypical units were tested as a separate BMG. In doing so,
the building owner obtained the following benefits:
• The 23 untested typical units could be managed as having no LBP on the Kitchen
walls or ceilings or the Bathroom interior walls and ceilings or on the Master
Bedroom baseboard. Had the bare minimum been done, these components would
all have been listed as positive for LBP.
• Having a separate set of atypical units known to have more LBP with a higher
rate of damage assists the owner in making decisions about leasing to young
couples or tenants with very young children and can direct maintenance
personnel to monitor these units more closely.