Cal. Civ. Code § 5:17-7.1

(a) An inspector/risk assessor shall fulfill the requirements as described in (b) and (c) below only if any of these conditions exist:
1. A site to be remediated contains bare play areas which are designated play areas or which contain children's play equipment or which areas are commonly used and known to be used by children as play areas;
2. Lead based paint is known or suspected to be on a building exterior and is known or suspected to be a health hazard or source of interior contamination;
3. Soil is known or suspected from prior usage to be contaminated with lead; or
4. The owner requests soil testing.
(b) The inspector/risk assessor shall recommend a soil sampling strategy of at least the following:
1. For a residential yard or playground, a composite sample of no more than 10 sub-samples of bare play areas if there are such areas;
2. A composite sample of no more than 10 sub-samples for a residential, daycare or school building along the building drip line;
3. A sample method to collect the top one-half inch of soil from areas to be sampled, and to include, but not oversample, paint chips or other contaminated debris in the soil; and
4. For sites other than residential, daycare or school uses, the inspector/risk assessor shall work with the owner to recommend an appropriate strategy.
(c) After receiving results of the sampling in (b) above from a qualified NLLAP certified laboratory or an equivalent independent national accreditation program, the inspector/risk assessor shall recommend at least the following interim controls or permanent abatement strategy:
1. Any areas testing more than or equal to 5,000 [mu] g/g lead shall be permanently abated by a method such as soil removal or paving; however, this requirement shall not supersede any Federal or State regulation which applies to any designated waste site or industrial area;
2. Any area expected to be used by children testing between 2,000 [mu] g/g and 5,000 [mu] g/g shall be permanently abated by a method such as paving over or soil removal. Areas where contact by children is unlikely may be treated with interim controls; and
3. Any area expected to be used by children testing between 400 [mu] g/g and 2,000 [mu] g/g shall be permanently abated as noted in (c)1 or 2 above, or may be subjected to interim controls.
i. Interim controls may include a change in usage pattern by moving play equipment, walkways or the like and planting thorny bushes or other ground cover, or installing fencing or other barriers to prevent use of contaminated areas.
ii. In low traffic areas, live ground cover, such as grass or shrubbery, or other cover such as clean soil, bark, or gravel may be used as an interim control. Clean soil or other cover shall be at least six inches in depth and shall be shown to contain not more than 200 [mu] g/g of lead.
iii. A plan for interim controls shall include a maintenance schedule to monitor use and to ensure that plantings and installations remain in place.
(d) After receiving results of the sampling in (b) above from a qualified NLLAP certified laboratory or an equivalent independent national accreditation program, the inspector/risk assessor shall recommend interim controls or permanent abatement, at the site of residential buildings or other child occupied facilities, so that:
1. The arithmetic mean of children's bare soil play areas shall be less than 400 [mu] g/g of lead when composites are analyzed;
2. The arithmetic mean of all other bare soil areas shall be less than 1,200 [mu] g/g of lead when composites are analyzed; and
3. Any soil removed pursuant to (d)1 or 2 above shall not be used as topsoil at any residential site or at the site of any child occupied facility.