Cal. Civ. Code § 5:17-9.1

(a) To allow lead dust to settle, the final inspection and clearance testing shall begin no sooner than one hour after the final cleaning is completed.
(b) The final inspection shall consist of a visual inspection to verify that all abated surfaces have been replaced, painted, or sealed, and the collection of environmental samples to ensure that the work area has been effectively cleaned.
1. Wipe samples shall be taken from the abated area, one sample from within 10 feet outside the containment area and one sample from any nearby high traffic area.
2. When an abatement project involves exterior abatement work, soil samples shall be collected around the foundation of the structure and in any play areas that could have been affected by the work. All soil samples shall be composite samples as described in (d) below.
(c) Single surface samples, which shall consist of one sample in a single, hard, rinsable container, shall be required for all abatement projects.
1. Single surface sampling shall follow the methodology at N.J.A.C. 5:17-3.3(d) of this chapter.
2. Single surface sampling shall comply in number and location with Table 9.1 below.
(d) Composite clearance samples, which shall consist of no more than four subsamples in a single container, are allowed for abatement projects where similar lead hazard control treatments were used in multiple rooms of the same dwelling. Composite sampling shall be performed in accordance with N.J.A.C. 5:17-3.4(c).
(e) The following lead dust levels are acceptable for clearance:
1. Floors--100 [micro]g/square foot;
2. Interior window sills--500 [micro]g/square foot; and
3. Window wells, exterior concrete, rough surfaces--800 [micro]g/square foot.
(f) The following lead dust levels are acceptable for clearance at residential buildings and child occupied facilities:
1. Floors--less than 10 [micro]g/square foot;
2. Interior window sills--less than 100 [micro]g/square foot;
3. Window wells--less than 400 [micro]g/square foot.
(g) Random sampling is permitted in multifamily buildings with 10 or more dwelling units where the units are similarly configured and have had comparable lead control activity, performed at the same time and using the same abatement contractor. The units to be tested shall not be selected until all abatement activity and cleaning have been completed.
(h) Field spiked samples shall be submitted and analyzed in accordance with the requirements of N.J.A.C. 5:17-3.3(d).
(i) All clearance samples shall be analyzed at a laboratory participating in the NLLAP program or an equivalent independent national accreditation program.

TABLE 9.1
Recommended Minimum Number and Location of Clearance Dust
Samples for All Abatement and Interim Control Work
Clearance Category Number and Location of Single-Surface Number and Location of Composite
Category Description Wipe Samples in Each Area * Wipe Samples
1 Interior treatments Two dust samples from every room in Three composite samples for every batch
dwelling (whether treated or untreated): of four rooms (whether treated or
untreated):
- One interior window sill or window - One floor composite
trough, alternating between rooms, - One interior window sill composite
- One floor - One window trough composite
No containment AND AND
within dwelling - For common areas, one for every 2,000 - For common areas, one floor subsample
ft<2> of a common area room floor for every 2,000 ft<2> (if present); up
(if present). to 8,000 ft<2> can be sampled
for each composite.

2 Interior treatments Same as Category 1, but only in every Same as Category 1, but only in every
treated room AND, treated room AND,
One floor sample outside One floor sample outside
the containment area but the containment area but
within 10 feet of the airlock within 10 feet of the airlock
to determine the effectiveness of the to determine the effectiveness of the
containment system. This extra containment system. (This extra
single-surface sample is recommended single-surface sample is recommended
in 20 percent of the treated dwellings in in 20 percent of the treated dwellings in
multifamily housing and multifamily housing and
With containment all single-family homes. all single-family homes.)
(plastic sheeting - For Common Areas, one floor - For Common Areas, one floor
as airlock on sample for every 2,000 ft<2> and one dunsample for every 2,000 ft<2>
doors between floor sample outside (up to 8,000 ft<2> for each composite)
treated and containment. and one floor sample outside
untreated areas) containment.
3 Exterior Two dust samples as follows: Two dust samples as follows:
treatments - At least one dust sample on a - One composite on a horizontal surface
horizontal surface in part of the in part of the outdoor living area
outdoor living area (e.g., a porch (e.g., a porch floor or entryway)
floor or entryway), and , and
- One window trough sample on - One window trough composite for
each floor where exterior work was every 4 floors where exterior work was
performed. An additional trough sample performed, including lower floors where
should be collected from a few lower exterior work was not done, if present.
floors to determine if troughs below the
area were contaminated by the work
above.
4 Soil Treatment One sample from the entryway. One sample from the entryway.

* A room includes a hallway or a stairway. If no window is present, collect just one floor sample. When a closet is treated, the room to which it is attached should be tested. A closet is not considered to be a separate room.

SOURCE: PRE-PUBLICATION COPY: Guidelines For The Evaluation And Control of Lead-Based Paint Hazards in Housing, The National Center for Lead-Safe Housing, February 1995.