{"main_topic":"health","sub_topic":"usda","topic":"food_access_2019","key":"health/usda/food_access_2019","version":"1.0.0","year_min":2019,"year_max":2019,"year_gaps":[],"update_frequency":"irregular","detail_levels":["counties","states"],"default_detail":"counties","path_template":"health/food_access_2019/year={year}/{detail}.parquet","grain":["year","county_fips","tract_geoid","distance_threshold"],"title":"Low Access to Supermarkets (USDA 2019 Map)","summary":"Share of residents living far from a supermarket or large grocery store, by county: USDA's 2019 store list and 2010 Census population.","description":"How many Georgians lived far from a supermarket, supercenter or large grocery store, for Georgia and each of its 159 counties, from the U.S. Department of Agriculture Economic Research Service's 2019 Large Retailer Access Map (formerly the Food Access Research Atlas): the residents (2010 Census) living more than a set straight-line distance from the nearest such store on ERS's 2019 store list, and their share of the population. USDA's main definition counts people more than 1 mile from a store in urban census tracts and more than 10 miles in rural tracts; two other urban/rural thresholds and four single distances (half a mile to 20 miles) are also served. County and state figures are our sums of ERS's 2010 census-tract counts.","explorer":true,"search_aliases":{"en":["supermarket access","distance to supermarket","far from groceries","large grocery stores","supercenters","food access atlas","healthy food access","grocery store access"],"es":["acceso a supermercados","distancia al supermercado","lejos del supermercado","supermercados grandes","supercentros","atlas de acceso alimentario","acceso a alimentos saludables","acceso a comestibles"]},"source":"U.S. Department of Agriculture, Economic Research Service: Food Access Research Atlas, 2019 Large Retailer Access Map (LRAM) data download (released April 2021; 2010 census tracts, 2010 Census population, 2019 store list), retrieved 2026-10-24. Citation: Rhone, Alana, et al., Food Access Research Atlas.","source_url":"https://www.ers.usda.gov/data-products/food-access-research-atlas/download-the-data","endpoint":"/api/v1/health/food_access_2019","columns":[{"name":"year","type":"integer","role":"year","nullable":false,"label":"Year","short_description":"","description":"2019, the year of ERS's supermarket list; the population is from the 2010 Census (see year_meaning). One release.","valid_values":null,"example":2019,"unit":null,"value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":false,"metric_component":null},{"name":"county_fips","type":"string","role":"fk_county","nullable":true,"label":"County FIPS","short_description":"","description":"5-digit county FIPS code (FK to the counties dimension): the first five digits of ERS's 2010 census tract codes. NULL on the Georgia (state) row.","valid_values":null,"example":"13121","unit":null,"value_min":null,"value_max":null,"null_meaning":"Statewide row (Georgia as a whole).","key_metric_grain_contributor":false,"metric_component":null},{"name":"tract_geoid","type":"string","role":"fk_tract","nullable":true,"label":"Tract GEOID","short_description":"","description":"Always NULL: ERS publishes 2010 census tracts, which do not join the 2020 tracts dimension, so figures are summed to counties. Kept for the health domain's standard key shape.","valid_values":null,"example":null,"unit":null,"value_min":null,"value_max":null,"null_meaning":"Always NULL (no tract rows).","key_metric_grain_contributor":false,"metric_component":null},{"name":"distance_threshold","type":"string","role":"categorical","nullable":false,"label":"Distance Threshold","short_description":"How far from a supermarket counts as low access; 1_mile_urban_10_miles_rural is USDA's main definition.","description":"The straight-line distance to the nearest supermarket, supercenter or large grocery store beyond which a resident counts as having low access. USDA's urban/rural definitions: 1_mile_urban_10_miles_rural (USDA's main definition: more than 1 mile in urban tracts, more than 10 miles in rural tracts), half_mile_urban_10_miles_rural and 1_mile_urban_20_miles_rural. One distance for every tract, urban or rural: all_tracts_half_mile, all_tracts_1_mile, all_tracts_10_miles and all_tracts_20_miles. ERS calls a tract rural when its population-weighted center is outside any urban area of 2,500 or more people. The thresholds nest (a resident beyond 1 mile is also beyond half a mile): pick one, never add across them.","valid_values":["1_mile_urban_10_miles_rural","half_mile_urban_10_miles_rural","1_mile_urban_20_miles_rural","all_tracts_half_mile","all_tracts_1_mile","all_tracts_10_miles","all_tracts_20_miles"],"example":"1_mile_urban_10_miles_rural","unit":null,"value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":true,"metric_component":null},{"name":"num_population_low_access","type":"integer","role":"metric","nullable":true,"label":"Residents with Low Access","short_description":"","description":"Residents (2010 Census) living beyond the distance threshold from the nearest supermarket, supercenter or large grocery store on ERS's 2019 list: the sum of ERS's 2010 census-tract counts in the county (or Georgia), a tract count ERS writes as NULL (no value) counted as 0. Our calculation. ERS's tract counts are whole-number estimates, so a 0 can be less than one person rounded down. The numerator of pct_population_low_access.","valid_values":null,"example":271723,"unit":"count","value_min":null,"value_max":null,"null_meaning":"Never NULL: ERS suppresses nothing, and a tract count ERS writes as NULL (no value: nobody beyond the distance) is summed as 0.","key_metric_grain_contributor":false,"metric_component":"numerator"},{"name":"num_population","type":"integer","role":"metric","nullable":true,"label":"Population (2010 Census)","short_description":"","description":"The county's (or Georgia's) 2010 Census population: the sum of ERS's 2010 census-tract populations (Georgia 9,687,653, the 2010 Census count). The same on every distance_threshold row of a place: never add it across thresholds. The denominator of pct_population_low_access.","valid_values":null,"example":920581,"unit":"count","value_min":null,"value_max":null,"null_meaning":"Never NULL: every Georgia tract in ERS's file has a 2010 Census population.","key_metric_grain_contributor":false,"metric_component":"denominator"},{"name":"pct_population_low_access","type":"number","role":"metric","nullable":true,"label":"Share of Residents with Low Access to a Supermarket","short_description":"Share of residents living beyond the distance threshold from the nearest supermarket, supercenter or large grocery store.","description":"Share of residents (2010 Census) living beyond the distance threshold, straight-line, from the nearest supermarket, supercenter or large grocery store on ERS's 2019 list: our calculation, num_population_low_access / num_population, on the 0-1 scale (0.309 = 30.9%). Georgia: 30.9% at USDA's main definition (1 mile urban / 10 miles rural), 55.8% at half a mile urban / 10 miles rural, 29.8% at 1 mile urban / 20 miles rural; 82.6% beyond half a mile and 54.8% beyond 1 mile in every tract, 1.1% beyond 10 miles and 452 people beyond 20 miles. Low access, not USDA's low-income and low-access ('food desert') tract designation. For several counties, pool as SUM(num_population_low_access) / SUM(num_population) within one threshold. Chattahoochee County's 97.6% at the main definition (the highest) is preserved as published: 29% of its residents live in group quarters, and the share is the same without them; food sources on the Army post may not be on ERS's 2019 store list.","valid_values":null,"example":0.2952,"unit":"proportion","value_min":null,"value_max":null,"null_meaning":"Never NULL: ERS suppresses nothing, and a tract count ERS writes as NULL (no value: nobody beyond the distance) is summed as 0.","key_metric_grain_contributor":false,"metric_component":null}],"key_metric":"pct_population_low_access","numeric_filter_columns":["num_population_low_access","num_population","pct_population_low_access"],"usage":"Star-schema fact table at state and county grain, one release (year 2019). Join the counties dimension on county_fips (NULL on the Georgia row); tract_geoid is always NULL. Always pin distance_threshold: 1_mile_urban_10_miles_rural is USDA's main low-access definition. The thresholds nest (people beyond 1 mile are also beyond half a mile), so never add rows across them. For several counties, pool as SUM(num_population_low_access) / SUM(num_population) within one threshold, never an average of county shares. num_population repeats on every threshold row of a place: never add it across thresholds. County rows add up exactly to the Georgia row. County and state figures are our calculation, sums of ERS's 2010 census-tract counts. Read directly with DuckDB over Parquet.","limitations":"One release, not a series: where Georgia's 2010 Census population lived relative to the supermarkets, supercenters and large grocery stores of 2019 (year 2019 labels the store list; see year_meaning). A resident has low access when the nearest such store is more than a set straight-line distance away: by USDA's main definition (distance_threshold 1_mile_urban_10_miles_rural) more than 1 mile in an urban census tract and more than 10 miles in a rural one. The thresholds nest: pick one. Not USDA's 'food desert' (low-income and low-access tract) designation: this counts everyone beyond the distance, at any income and in any tract. County and state figures are our calculation: ERS publishes 2010 census tracts, which do not match the 2020 tracts, so each county row sums its tracts' counts and 2010 populations (Georgia's 159 counties did not change between 2010 and 2020) and the share is the summed count over the summed population. Distance is straight-line, from the center of each half-kilometer grid cell where ERS placed the population (from 2010 census blocks) to the center of the cell with the nearest store: not travel distance, and blind to roads, vehicles, transit, prices and store quality. Other food sources (convenience and dollar stores, small grocers, farmers' markets) do not count. A county's figure at the urban/rural thresholds mixes its urban tracts (the 1-mile or half-mile rule) and its rural tracts (10 or 20 miles); ERS calls a tract rural when its population-weighted center is outside any urban area of 2,500 or more people. Where nobody lives beyond the distance, ERS writes NULL (no value) in place of a tract's count; those tracts count as 0 here (ERS flags none of them as low access at that distance, and none has anyone at a farther distance). Tract counts are ERS's whole-number estimates, so a 0, a tract's or a county's, can be a fraction of a person rounded down rather than nobody (a few tracts show a count of 0 beside a positive share), and sums can differ by a few people from ERS's own unrounded county figures. Residents of group quarters (dormitories, barracks, prisons, nursing homes: 253,199 Georgians in ERS's file) count where they live, though many have food provided on site; ERS marks 10 Georgia tracts where at least 67% of residents live in group quarters. Not comparable with USDA's 2025 SNAP-authorized Retailer Access Map (SRAM): it counts any SNAP-authorized store (including convenience and dollar stores), on 2020 tracts with 2020 population, so never splice the two or read a trend between them. ERS expects a new version of this map in winter 2026-27, which would be a separate release. ERS's file lists 1,957 Georgia tracts; the 2010 tracts it leaves out have no residents (its population adds up to Georgia's 2010 Census count, 9,687,653). ERS suppresses nothing, and there are no NULLs; a 0 means nobody, or by ERS's estimate less than one person, lives beyond the distance. Not served: ERS's counts for low-income people, children, seniors, race and ethnicity groups and households without a vehicle, its tract flags, and tract rows. tract_geoid is always NULL.","null_semantics":{"suppressed_to_null":false,"zero_is_real":false},"available_years":[2019],"schema_hash":"7ec2e12494bc15b0c0fc6383971744a23b3d0544477b5e5aa30bfa0af5fc75a9","tags":["health","u.s. department of agriculture, economic research service: food access research atlas, 2019 large retailer access map","food_access_2019"],"granularity_description":"One row per year, county_fips, tract_geoid, distance_threshold (geography columns are NULL at higher aggregation levels).","example_queries":[{"description":"Latest year (2019), counties detail","query":"SELECT * FROM food_access_2019 WHERE year = 2019 LIMIT 100"},{"description":"Filter by distance_threshold = 1_mile_urban_10_miles_rural","query":"SELECT * FROM food_access_2019 WHERE distance_threshold = '1_mile_urban_10_miles_rural' AND year = 2019 LIMIT 100"}],"foreign_keys":[{"column":"county_fips","target_object":"counties","target_columns":["county_fips"],"attribute_columns_added":["county_name"],"scope":"global"},{"column":"tract_geoid","target_object":"tracts","target_columns":["tract_geoid"],"attribute_columns_added":["tract_name"],"scope":"global"}],"filters":[{"param":"year","kind":"year_exact","type":"integer","multi_value":false,"enum_enforced":false,"values":null},{"param":"year_min","kind":"year_range","type":"integer","multi_value":false,"enum_enforced":false,"values":null},{"param":"year_max","kind":"year_range","type":"integer","multi_value":false,"enum_enforced":false,"values":null},{"param":"detail","kind":"detail","type":"string","multi_value":false,"enum_enforced":true,"values":["counties","states"],"default":"counties"},{"param":"county_fips","kind":"foreign_key","column":"county_fips","type":"string","multi_value":true,"enum_enforced":false,"values":null},{"param":"tract_geoid","kind":"foreign_key","column":"tract_geoid","type":"string","multi_value":true,"enum_enforced":false,"values":null},{"param":"distance_threshold","kind":"categorical","column":"distance_threshold","type":"string","multi_value":true,"enum_enforced":true,"values":["1_mile_urban_10_miles_rural","half_mile_urban_10_miles_rural","1_mile_urban_20_miles_rural","all_tracts_half_mile","all_tracts_1_mile","all_tracts_10_miles","all_tracts_20_miles"],"has_total":false,"total_value":null,"requires_single_value":true,"nullable":false,"null_filter_token":null}],"filter_hints":[],"non_additive":[{"column":"distance_threshold","reason":"The thresholds count the same residents at different distances: everyone beyond 1 mile is also beyond half a mile, and the urban/rural definitions overlap the single distances they are built from. num_population is the place's whole 2010 population, repeated on every threshold row. A sum across thresholds is not a total: pick one threshold."}],"partitions":[],"value_implications":[],"year_meaning":"year 2019 is the year of ERS's store list: the supermarkets, supercenters and large grocery stores located as of 2019 (USDA's list of SNAP-authorized stores merged with the TDLinx store directory). The people counted are the 2010 Census population, so each figure says how many 2010 residents lived far from a 2019 store, not how many Georgians lived far from a store in 2019. ERS's low-income measures, which use incomes from the 2014-2018 American Community Survey, are not in this table. ERS released the map in April 2021; it is one release, not a series, and no other year is in this table.","pooled_rates":[],"series_breaks":[],"year_window":null,"pooled_min_count":null,"values_endpoint":"/api/v1/health/food_access_2019/values"}