{
  "city": "Los Angeles",
  "state": "CA",
  "slug": "los-angeles",
  "hardness_facts": [
    {
      "utility": "LADWP",
      "measure": "Total hardness, Los Angeles Aqueduct plant",
      "value_as_published": "Average 103 mg/L, range 96-117 mg/L",
      "period": "Calendar year 2025",
      "source_title": "Drinking Water Quality Report 2025 (LADWP), Table III",
      "source_url": "https://www.ladwp.com/sites/default/files/2026-07/2026_DWQR_Print_Rev2_Digital-remediated.pdf"
    },
    {
      "utility": "LADWP",
      "measure": "Total hardness, northern wells",
      "value_as_published": "Average 115 mg/L, range 78-151 mg/L",
      "period": "Calendar year 2025",
      "source_title": "Drinking Water Quality Report 2025 (LADWP), Table III",
      "source_url": "https://www.ladwp.com/sites/default/files/2026-07/2026_DWQR_Print_Rev2_Digital-remediated.pdf"
    },
    {
      "utility": "LADWP",
      "measure": "Total hardness, southern wells",
      "value_as_published": "Average 116 mg/L, range 83-159 mg/L",
      "period": "Calendar year 2025",
      "source_title": "Drinking Water Quality Report 2025 (LADWP), Table III",
      "source_url": "https://www.ladwp.com/sites/default/files/2026-07/2026_DWQR_Print_Rev2_Digital-remediated.pdf"
    },
    {
      "utility": "LADWP",
      "measure": "Total hardness, MWD Weymouth plant",
      "value_as_published": "Average 234 mg/L, range 189-280 mg/L",
      "period": "Calendar year 2025",
      "source_title": "Drinking Water Quality Report 2025 (LADWP), Table III",
      "source_url": "https://www.ladwp.com/sites/default/files/2026-07/2026_DWQR_Print_Rev2_Digital-remediated.pdf"
    },
    {
      "utility": "LADWP",
      "measure": "Total hardness, MWD Diemer plant",
      "value_as_published": "Average 236 mg/L, range 191-280 mg/L",
      "period": "Calendar year 2025",
      "source_title": "Drinking Water Quality Report 2025 (LADWP), Table III",
      "source_url": "https://www.ladwp.com/sites/default/files/2026-07/2026_DWQR_Print_Rev2_Digital-remediated.pdf"
    },
    {
      "utility": "LADWP",
      "measure": "Total hardness, MWD Jensen plant",
      "value_as_published": "Average 140 mg/L, range 137-142 mg/L",
      "period": "Calendar year 2025",
      "source_title": "Drinking Water Quality Report 2025 (LADWP), Table III",
      "source_url": "https://www.ladwp.com/sites/default/files/2026-07/2026_DWQR_Print_Rev2_Digital-remediated.pdf"
    }
  ],
  "published_span_mg_per_l": [
    78,
    280
  ],
  "span_converted_from_grains": false,
  "usgs_class": "moderately hard to very hard",
  "usgs_class_source": "https://www.usgs.gov/water-science-school/science/hardness-water",
  "notes": [
    "In 2025 the Aqueduct supplied 44 percent and Metropolitan Water District water 52 percent.",
    "LADWP's FAQ gives older 2022 figures by area: about 8.6 grains per gallon in the San Fernando Valley and western Los Angeles, and about 16.3 in eastern Los Angeles and the Harbor."
  ],
  "local_details": {
    "disinfectant": {
      "text": "LADWP disinfects its drinking water with chloramine.",
      "kind": "chloramine",
      "source_title": "LADWP 2026 Drinking Water Quality Report",
      "source_url": "https://www.ladwp.com/sites/default/files/2026-07/2026_DWQR_Print_Rev2_Digital-remediated.pdf",
      "evidence_ids": [
        "LOSANG-L-01"
      ]
    },
    "source_water": {
      "text": "In 2025, 44 percent of LADWP water came from the Los Angeles Aqueduct, 52 percent was bought from the Metropolitan Water District (State Water Project and Colorado River), 1 percent was local groundwater and 3 percent was recycled water.",
      "source_title": "LADWP 2026 Drinking Water Quality Report",
      "source_url": "https://www.ladwp.com/sites/default/files/2026-07/2026_DWQR_Print_Rev2_Digital-remediated.pdf",
      "evidence_ids": [
        "LOSANG-L-02"
      ]
    },
    "by_area": {
      "text": "LADWP reports by community zone, and says the sources serving a zone can change with operations and supply, so water differs across the city.",
      "source_title": "LADWP 2026 Drinking Water Quality Report",
      "source_url": "https://www.ladwp.com/sites/default/files/2026-07/2026_DWQR_Print_Rev2_Digital-remediated.pdf",
      "evidence_ids": [
        "LOSANG-L-03"
      ]
    }
  },
  "sources_checked_on": "2026-10-27",
  "site": "https://losangeleswatersystems.com/",
  "brand": "Los Angeles Water Systems by My Home Water System",
  "taking_requests": true
}