{
  "method": "One residential assessor parcel with housing units > 0 and valid year 1800-2026, joined to a county address point inside the official city polygon. Prefer primary address then lowest county object ID. Point-in-polygon overlay of Utah 2024-reporting-year culinary service areas. ZIP means address ZIP within the city, not whole ZIP. Not dwelling/customer counts or observed pipe materials.",
  "analysis_date": "2026-09-11",
  "tax_years": {
    "2025": 10842
  },
  "invalid_residential_years": 1,
  "all": {
    "records": 10842,
    "median_year": 1964.0,
    "from1990to2009": 1461,
    "before2005": 9612,
    "before1980": 7660,
    "before1986": 8207,
    "decades": {
      "1860": 1,
      "1870": 3,
      "1880": 5,
      "1890": 9,
      "1900": 24,
      "1910": 27,
      "1920": 98,
      "1930": 154,
      "1940": 307,
      "1950": 3082,
      "1960": 2307,
      "1970": 1643,
      "1980": 862,
      "1990": 827,
      "2000": 634,
      "2010": 604,
      "2020": 255
    }
  },
  "by_zip": {
    "84117": {
      "records": 5698,
      "median_year": 1970.0,
      "from1990to2009": 683,
      "before2005": 4947,
      "before1980": 3955,
      "before1986": 4368,
      "decades": {
        "1870": 2,
        "1880": 2,
        "1890": 7,
        "1900": 11,
        "1910": 12,
        "1920": 65,
        "1930": 91,
        "1940": 158,
        "1950": 1097,
        "1960": 1388,
        "1970": 1122,
        "1980": 527,
        "1990": 338,
        "2000": 345,
        "2010": 334,
        "2020": 199
      }
    },
    "84121": {
      "records": 1682,
      "median_year": 1974.0,
      "from1990to2009": 464,
      "before2005": 1432,
      "before1980": 914,
      "before1986": 980,
      "decades": {
        "1880": 2,
        "1900": 5,
        "1910": 6,
        "1920": 16,
        "1930": 11,
        "1940": 44,
        "1950": 261,
        "1960": 292,
        "1970": 277,
        "1980": 138,
        "1990": 302,
        "2000": 162,
        "2010": 134,
        "2020": 32
      }
    },
    "84124": {
      "records": 3462,
      "median_year": 1959.0,
      "from1990to2009": 314,
      "before2005": 3233,
      "before1980": 2791,
      "before1986": 2859,
      "decades": {
        "1860": 1,
        "1870": 1,
        "1880": 1,
        "1890": 2,
        "1900": 8,
        "1910": 9,
        "1920": 17,
        "1930": 52,
        "1940": 105,
        "1950": 1724,
        "1960": 627,
        "1970": 244,
        "1980": 197,
        "1990": 187,
        "2000": 127,
        "2010": 136,
        "2020": 24
      }
    }
  },
  "overlap": 0,
  "unmatched": 0,
  "providers": {
    "Holliday Water Co.": {
      "records": 4154,
      "median_year": 1964.0,
      "from1990to2009": 575,
      "before2005": 3541,
      "before1980": 2865,
      "before1986": 3046,
      "decades": {
        "1860": 1,
        "1870": 1,
        "1880": 3,
        "1890": 3,
        "1900": 13,
        "1910": 16,
        "1920": 67,
        "1930": 120,
        "1940": 236,
        "1950": 852,
        "1960": 1028,
        "1970": 525,
        "1980": 293,
        "1990": 256,
        "2000": 319,
        "2010": 270,
        "2020": 151
      },
      "by_zip": {
        "84124": 1439,
        "84117": 2678,
        "84121": 37
      }
    },
    "Jordan Valley Water Conservancy District (Retail)": {
      "records": 339,
      "median_year": 1972,
      "from1990to2009": 17,
      "before2005": 310,
      "before1980": 270,
      "before1986": 285,
      "decades": {
        "1900": 1,
        "1910": 1,
        "1920": 5,
        "1930": 6,
        "1940": 3,
        "1950": 53,
        "1960": 84,
        "1970": 117,
        "1980": 27,
        "1990": 5,
        "2000": 12,
        "2010": 22,
        "2020": 3
      },
      "by_zip": {
        "84117": 339
      }
    },
    "Salt Lake City Water System": {
      "records": 6349,
      "median_year": 1964,
      "from1990to2009": 869,
      "before2005": 5761,
      "before1980": 4525,
      "before1986": 4876,
      "decades": {
        "1870": 2,
        "1880": 2,
        "1890": 6,
        "1900": 10,
        "1910": 10,
        "1920": 26,
        "1930": 28,
        "1940": 68,
        "1950": 2177,
        "1960": 1195,
        "1970": 1001,
        "1980": 542,
        "1990": 566,
        "2000": 303,
        "2010": 312,
        "2020": 101
      },
      "by_zip": {
        "84124": 2023,
        "84117": 2681,
        "84121": 1645
      }
    }
  },
  "publisher": "Mountain Man Plumbing",
  "area": "Holladay, Utah",
  "sources": [
    {
      "dataset": "slco-parcel-owners.ndjson",
      "sha256": "d970d9aa0c85e6664637ee5046495c42ed0985aa36afe5a540a8b71876ef3de0"
    },
    {
      "dataset": "features.arcgis.ndjson",
      "sha256": "2fb8a47f1c8cfe8c6745e0898baf29f413cd7d3c7e8afce35b63c763f881e1ad"
    },
    {
      "dataset": "features.geojson",
      "sha256": "b7862cb103e1e911864826dc9f75d5327d1e16b2697c0a5b687ff2dc3a884086"
    },
    {
      "dataset": "ugrc_culinary_water_service_areas_slco.features.arcgis.ndjson",
      "sha256": "75854de6965161fac9f7f55347d143e515753149919ef10d81ddd958464d82c1"
    }
  ],
  "notes": [
    "No individual parcel locations or owner information are published.",
    "Mapped parcel counts are not utility customer accounts. Service boundaries use the 2024 reporting year.",
    "Construction dates do not identify the plumbing now installed."
  ]
}