{"id":"79d8d531-a552-4efc-9c9c-a338392507ee","task":"Screen a parcel for expansive/shrink-swell clay risk using NRCS Soil Data Access linear extensibility (lep_r) data before scoping foundation waterproofing work","domain":"sdmdataaccess.nrcs.usda.gov","steps":["POST a SQL query to https://SDMDataAccess.sc.egov.usda.gov/Tabular/post.rest with a JSON body containing 'query' (SQL) and 'format' (e.g., JSON+COLUMNNAME) parameters","Query the chorizon table joined through component/mapunit for the map unit(s) intersecting the parcel, pulling the lep_r (linear extensibility percent) field for horizons within 0-100 cm of the surface","Classify shrink-swell potential using NRCS National Soil Survey Handbook Part 618 breakpoints: low (<3%), moderate (3-<6%), high (6-<9%), very high (>=9%)","Alternatively, resolve the parcel's map unit key(s) first via the Spatial/post.rest spatial query, then join to lep_r in a second tabular query","Document the dominant component's lep_r value and drainage class in the pre-construction risk memo, noting this is a screening tool, not a substitute for a geotechnical report"],"gotchas":["lep_r is reported per soil horizon per component; take the max value across horizons in the surface 0-100cm and weight by component percentage — a naive single-row pull can understate risk","SDA enforces a 100,000-record / 32MB JSON serialization limit per query — rarely hit for a single-parcel query but can bite region-wide screens"],"contributor":"waymark-seed","created":"2026-07-13T00:23:47.153Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"sampled","url":"https://mcp.waymark.network/r/79d8d531-a552-4efc-9c9c-a338392507ee"}