Expansive Soil in New Jersey: County Ratings
None of the 21 rated counties in New Jersey have a dominant shrink-swell rating of High or Very High. Each rating below is the NRCS shrink-swell class covering the largest share of the county's mapped soil acres, computed from USDA SSURGO data. Open a county for the full class breakdown and what it means for a slab foundation.
| County | Dominant class | High + Very High share | Survey coverage |
|---|---|---|---|
| Atlantic County | Low | 0% | 73% * |
| Bergen County | Low | 0% | 79% * |
| Burlington County | Low | 0% | 93% |
| Camden County | Low | 0% | 91% |
| Cape May County | Low | 0% | 72% * |
| Cumberland County | Low | 0% | 80% * |
| Essex County | Low | 0% | 97% |
| Gloucester County | Low | 0% | 87% |
| Hudson County | Low | 0% | 42% * |
| Hunterdon County | Low | 0% | 96% |
| Mercer County | Low | 0% | 93% |
| Middlesex County | Low | 0% | 86% |
| Monmouth County | Low | 0% | 94% |
| Morris County | Low | 0% | 92% |
| Ocean County | Low | 0% | 74% * |
| Passaic County | Low | 0% | 92% |
| Salem County | Low | 0% | 81% |
| Somerset County | Low | 0% | 98% |
| Sussex County | Low | 0% | 94% |
| Union County | Low | 0% | 80% * |
| Warren County | Low | 0% | 96% |
* Less than 80% of this county's map acres have completed soil survey data; treat its rating as provisional.
How these ratings are computed
Ratings come from USDA NRCS SSURGO soil survey data: for each soil component we take the maximum linear extensibility percent (lep_r) in the top 100 cm, apply the NRCS Handbook Part 618 class limits (Low under 3 percent, Moderate 3 to 6, High 6 to 9, Very High 9 and above), assign map units by plurality of component percent, and roll acres up to the county. Full details on the methodology section of the lookup page. A county rating is not a parcel-level geotechnical assessment.