Pennsylvania · drinking water · SDWIS through latest publish

Horsham Water&Sewer Authority Water Quality — Horsham, Pennsylvania

PWSID PA1460033 · Purchased / wholesaleMunicipal

26,000 people served. No health-based SDWIS violations recorded in the past 5 years. 1 remains unresolved. Last cited 2 years ago.

ALL SDWIS VIOLATIONS · 20202026 (annual count)
Bar chart of annual values from 2020 to 2026, in violations. Most recent year (2026): 0 violations.196 violations'20'21'22'23'24'25'260 violations
Anomaly engine

Active signals

UNRESOLVED VIOLATION · SDWIS VIOLATION

Contaminant 4030

Unresolved Phase I/II/V Inorganic Chemical Rules violation cited in 2024 (contaminant 4030).

EPA SDWIS record

Most-cited contaminants

What This Utility Gets Cited For

  • Contaminant 07009 citations
  • Endrin4 citations
  • Lindane4 citations
  • Methoxychlor4 citations
  • Toxaphene4 citations
  • Contaminant 20314 citations
Violation history

What's On The SDWIS Record

Health-based violations exceed an MCL or treatment-technique standard. Monitoring violations are reporting failures with no measured exceedance — they tell you the system isn't fully transparent, not that the water is unsafe today.

MONITORING · ENDRIN

2024 · Endrin · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2005

MONITORING · ENDRIN

2024 · Endrin · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2005

MONITORING · LINDANE

2024 · Lindane · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2010

MONITORING · LINDANE

2024 · Lindane · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2010

MONITORING · METHOXYCHLOR

2024 · Methoxychlor · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2015

MONITORING · METHOXYCHLOR

2024 · Methoxychlor · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2015

MONITORING · TOXAPHENE

2024 · Toxaphene · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2020

MONITORING · TOXAPHENE

2024 · Toxaphene · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2020

MONITORING · CONTAMINANT 2031

2024 · Contaminant 2031 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2031

MONITORING · CONTAMINANT 2031

2024 · Contaminant 2031 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2031

MONITORING · CONTAMINANT 2032

2024 · Contaminant 2032 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2032

MONITORING · CONTAMINANT 2032

2024 · Contaminant 2032 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2032

MONITORING · CONTAMINANT 2034

2024 · Contaminant 2034 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2034

MONITORING · CONTAMINANT 2034

2024 · Contaminant 2034 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2034

MONITORING · CONTAMINANT 2035

2024 · Contaminant 2035 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2035

MONITORING · CONTAMINANT 2035

2024 · Contaminant 2035 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2035

MONITORING · CONTAMINANT 2036

2024 · Contaminant 2036 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2036

MONITORING · CONTAMINANT 2036

2024 · Contaminant 2036 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2036

MONITORING · CONTAMINANT 2037

2024 · Contaminant 2037 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2037

MONITORING · CONTAMINANT 2037

2024 · Contaminant 2037 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2037

MONITORING · CONTAMINANT 2039

2024 · Contaminant 2039 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2039

MONITORING · CONTAMINANT 2039

2024 · Contaminant 2039 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2039

MONITORING · CONTAMINANT 2040

2024 · Contaminant 2040 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2040

MONITORING · CONTAMINANT 2040

2024 · Contaminant 2040 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2040

MONITORING · CONTAMINANT 2041

2024 · Contaminant 2041 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2041

MONITORING · CONTAMINANT 2041

2024 · Contaminant 2041 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2041

MONITORING · CONTAMINANT 2042

2024 · Contaminant 2042 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2042

MONITORING · CONTAMINANT 2042

2024 · Contaminant 2042 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2042

MONITORING · CONTAMINANT 2046

2024 · Contaminant 2046 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2046

MONITORING · CONTAMINANT 2046

2024 · Contaminant 2046 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2046

MONITORING · 2,4-D

2024 · 2,4-D · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2050

MONITORING · 2,4-D

2024 · 2,4-D · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2050

MONITORING · CONTAMINANT 2051

2024 · Contaminant 2051 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2051

MONITORING · CONTAMINANT 2051

2024 · Contaminant 2051 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2051

MONITORING · 2,4,5-TP (SILVEX)

2024 · 2,4,5-TP (Silvex) · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2065

MONITORING · 2,4,5-TP (SILVEX)

2024 · 2,4,5-TP (Silvex) · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2065

MONITORING · CONTAMINANT 2067

2024 · Contaminant 2067 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2067

MONITORING · CONTAMINANT 2067

2024 · Contaminant 2067 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2067

MONITORING · ALACHLOR

2024 · Alachlor · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2105

MONITORING · ALACHLOR

2024 · Alachlor · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2105

MONITORING · ATRAZINE

2024 · Atrazine · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2110

MONITORING · ATRAZINE

2024 · Atrazine · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2110

MONITORING · CONTAMINANT 2274

2024 · Contaminant 2274 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2274

MONITORING · CONTAMINANT 2274

2024 · Contaminant 2274 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2274

MONITORING · CARBOFURAN

2024 · Carbofuran · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2306

MONITORING · CARBOFURAN

2024 · Carbofuran · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2306

MONITORING · CONTAMINANT 2326

2024 · Contaminant 2326 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2326

MONITORING · CONTAMINANT 2326

2024 · Contaminant 2326 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2326

MONITORING · TRICHLOROETHYLENE (TCE)

2024 · Trichloroethylene (TCE) · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2383

MONITORING · TRICHLOROETHYLENE (TCE)

2024 · Trichloroethylene (TCE) · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2383

MONITORING · CONTAMINANT 2931

2024 · Contaminant 2931 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2931

MONITORING · CONTAMINANT 2931

2024 · Contaminant 2931 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2931

MONITORING · CONTAMINANT 2946

2024 · Contaminant 2946 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2946

MONITORING · CONTAMINANT 2946

2024 · Contaminant 2946 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2946

MONITORING · CONTAMINANT 2959

2024 · Contaminant 2959 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2959

MONITORING · CONTAMINANT 2959

2024 · Contaminant 2959 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2959

MONITORING · XYLENES (TOTAL)

2024 · Xylenes (total) · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2378

MONITORING · XYLENES (TOTAL)

2024 · Xylenes (total) · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2378

MONITORING · BENZENE

2024 · Benzene · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2380

MONITORING · BENZENE

2024 · Benzene · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2380

MONITORING · CONTAMINANT 2955

2024 · Contaminant 2955 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2955

MONITORING · CONTAMINANT 2955

2024 · Contaminant 2955 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2955

MONITORING · CONTAMINANT 2964

2024 · Contaminant 2964 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2964

MONITORING · CONTAMINANT 2964

2024 · Contaminant 2964 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2964

MONITORING · CONTAMINANT 2968

2024 · Contaminant 2968 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2968

MONITORING · CONTAMINANT 2968

2024 · Contaminant 2968 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2968

MONITORING · CONTAMINANT 2969

2024 · Contaminant 2969 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2969

MONITORING · CONTAMINANT 2969

2024 · Contaminant 2969 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2969

MONITORING · CONTAMINANT 2977

2024 · Contaminant 2977 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2977

MONITORING · CONTAMINANT 2977

2024 · Contaminant 2977 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2977

MONITORING · CONTAMINANT 2979

2024 · Contaminant 2979 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2979

MONITORING · CONTAMINANT 2979

2024 · Contaminant 2979 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2979

MONITORING · METHYL TERT-BUTYL ETHER (MTBE)

2024 · Methyl tert-butyl ether (MTBE) · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2980

MONITORING · METHYL TERT-BUTYL ETHER (MTBE)

2024 · Methyl tert-butyl ether (MTBE) · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2980

MONITORING · CONTAMINANT 2981

2024 · Contaminant 2981 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2981

MONITORING · CONTAMINANT 2981

2024 · Contaminant 2981 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2981

MONITORING · CONTAMINANT 2982

2024 · Contaminant 2982 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2982

MONITORING · CONTAMINANT 2982

2024 · Contaminant 2982 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2982

MONITORING · CONTAMINANT 2983

2024 · Contaminant 2983 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2983

MONITORING · CONTAMINANT 2983

2024 · Contaminant 2983 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2983

MONITORING · CONTAMINANT 2984

2024 · Contaminant 2984 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2984

MONITORING · CONTAMINANT 2984

2024 · Contaminant 2984 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2984

MONITORING · CONTAMINANT 2985

2024 · Contaminant 2985 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2985

MONITORING · CONTAMINANT 2985

2024 · Contaminant 2985 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2985

MONITORING · CONTAMINANT 2987

2024 · Contaminant 2987 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2987

MONITORING · CONTAMINANT 2987

2024 · Contaminant 2987 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2987

MONITORING · CONTAMINANT 2989

2024 · Contaminant 2989 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2989

MONITORING · CONTAMINANT 2989

2024 · Contaminant 2989 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2989

MONITORING · CONTAMINANT 2990

2024 · Contaminant 2990 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2990

MONITORING · CONTAMINANT 2990

2024 · Contaminant 2990 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2990

MONITORING · CONTAMINANT 2991

2024 · Contaminant 2991 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2991

MONITORING · CONTAMINANT 2991

2024 · Contaminant 2991 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2991

MONITORING · CONTAMINANT 2992

2024 · Contaminant 2992 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2992

MONITORING · CONTAMINANT 2992

2024 · Contaminant 2992 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2992

MONITORING · CONTAMINANT 2996

2024 · Contaminant 2996 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2996

MONITORING · CONTAMINANT 2996

2024 · Contaminant 2996 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2996

MONITORING · ENDRIN

2024 · Endrin · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2005

MONITORING · ENDRIN

2024 · Endrin · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2005

MONITORING · LINDANE

2024 · Lindane · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2010

MONITORING · LINDANE

2024 · Lindane · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2010

MONITORING · METHOXYCHLOR

2024 · Methoxychlor · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2015

MONITORING · METHOXYCHLOR

2024 · Methoxychlor · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2015

MONITORING · TOXAPHENE

2024 · Toxaphene · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2020

MONITORING · TOXAPHENE

2024 · Toxaphene · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2020

MONITORING · CONTAMINANT 2031

2024 · Contaminant 2031 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2031

MONITORING · CONTAMINANT 2031

2024 · Contaminant 2031 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2031

MONITORING · CONTAMINANT 2032

2024 · Contaminant 2032 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2032

MONITORING · CONTAMINANT 2032

2024 · Contaminant 2032 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2032

MONITORING · CONTAMINANT 2034

2024 · Contaminant 2034 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2034

MONITORING · CONTAMINANT 2034

2024 · Contaminant 2034 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2034

MONITORING · CONTAMINANT 2035

2024 · Contaminant 2035 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2035

MONITORING · CONTAMINANT 2035

2024 · Contaminant 2035 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2035

MONITORING · CONTAMINANT 2036

2024 · Contaminant 2036 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2036

MONITORING · CONTAMINANT 2036

2024 · Contaminant 2036 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2036

MONITORING · CONTAMINANT 2037

2024 · Contaminant 2037 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2037

MONITORING · CONTAMINANT 2037

2024 · Contaminant 2037 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2037

MONITORING · CONTAMINANT 2039

2024 · Contaminant 2039 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2039

MONITORING · CONTAMINANT 2039

2024 · Contaminant 2039 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2039

MONITORING · CONTAMINANT 2040

2024 · Contaminant 2040 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2040

MONITORING · CONTAMINANT 2040

2024 · Contaminant 2040 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2040

MONITORING · CONTAMINANT 2041

2024 · Contaminant 2041 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2041

MONITORING · CONTAMINANT 2041

2024 · Contaminant 2041 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2041

MONITORING · CONTAMINANT 2042

2024 · Contaminant 2042 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2042

MONITORING · CONTAMINANT 2042

2024 · Contaminant 2042 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2042

MONITORING · CONTAMINANT 2046

2024 · Contaminant 2046 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2046

MONITORING · CONTAMINANT 2046

2024 · Contaminant 2046 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2046

MONITORING · 2,4-D

2024 · 2,4-D · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2050

MONITORING · 2,4-D

2024 · 2,4-D · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2050

MONITORING · CONTAMINANT 2051

2024 · Contaminant 2051 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2051

MONITORING · CONTAMINANT 2051

2024 · Contaminant 2051 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2051

MONITORING · 2,4,5-TP (SILVEX)

2024 · 2,4,5-TP (Silvex) · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2065

MONITORING · 2,4,5-TP (SILVEX)

2024 · 2,4,5-TP (Silvex) · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2065

MONITORING · CONTAMINANT 2067

2024 · Contaminant 2067 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2067

MONITORING · CONTAMINANT 2067

2024 · Contaminant 2067 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2067

MONITORING · ALACHLOR

2024 · Alachlor · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2105

MONITORING · ALACHLOR

2024 · Alachlor · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2105

MONITORING · ATRAZINE

2024 · Atrazine · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2110

MONITORING · ATRAZINE

2024 · Atrazine · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2110

MONITORING · CONTAMINANT 2274

2024 · Contaminant 2274 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2274

MONITORING · CONTAMINANT 2274

2024 · Contaminant 2274 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2274

MONITORING · CARBOFURAN

2024 · Carbofuran · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2306

MONITORING · CARBOFURAN

2024 · Carbofuran · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2306

MONITORING · CONTAMINANT 2326

2024 · Contaminant 2326 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2326

MONITORING · CONTAMINANT 2326

2024 · Contaminant 2326 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2326

MONITORING · TRICHLOROETHYLENE (TCE)

2024 · Trichloroethylene (TCE) · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2383

MONITORING · TRICHLOROETHYLENE (TCE)

2024 · Trichloroethylene (TCE) · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2383

MONITORING · CONTAMINANT 2931

2024 · Contaminant 2931 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2931

MONITORING · CONTAMINANT 2931

2024 · Contaminant 2931 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2931

MONITORING · CONTAMINANT 2946

2024 · Contaminant 2946 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2946

MONITORING · CONTAMINANT 2946

2024 · Contaminant 2946 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2946

MONITORING · CONTAMINANT 2959

2024 · Contaminant 2959 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2959

MONITORING · CONTAMINANT 2959

2024 · Contaminant 2959 · Nitrate/Nitrite

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2959

MONITORING · XYLENES (TOTAL)

2024 · Xylenes (total) · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2378

MONITORING · XYLENES (TOTAL)

2024 · Xylenes (total) · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2378

MONITORING · BENZENE

2024 · Benzene · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2380

MONITORING · BENZENE

2024 · Benzene · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2380

MONITORING · CONTAMINANT 2955

2024 · Contaminant 2955 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2955

MONITORING · CONTAMINANT 2955

2024 · Contaminant 2955 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2955

MONITORING · CONTAMINANT 2964

2024 · Contaminant 2964 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2964

MONITORING · CONTAMINANT 2964

2024 · Contaminant 2964 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2964

MONITORING · CONTAMINANT 2968

2024 · Contaminant 2968 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2968

MONITORING · CONTAMINANT 2968

2024 · Contaminant 2968 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2968

MONITORING · CONTAMINANT 2969

2024 · Contaminant 2969 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2969

MONITORING · CONTAMINANT 2969

2024 · Contaminant 2969 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2969

MONITORING · CONTAMINANT 2977

2024 · Contaminant 2977 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2977

MONITORING · CONTAMINANT 2977

2024 · Contaminant 2977 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2977

MONITORING · CONTAMINANT 2979

2024 · Contaminant 2979 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2979

MONITORING · CONTAMINANT 2979

2024 · Contaminant 2979 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2979

MONITORING · METHYL TERT-BUTYL ETHER (MTBE)

2024 · Methyl tert-butyl ether (MTBE) · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2980

MONITORING · METHYL TERT-BUTYL ETHER (MTBE)

2024 · Methyl tert-butyl ether (MTBE) · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2980

MONITORING · CONTAMINANT 2981

2024 · Contaminant 2981 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2981

MONITORING · CONTAMINANT 2981

2024 · Contaminant 2981 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2981

MONITORING · CONTAMINANT 2982

2024 · Contaminant 2982 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2982

MONITORING · CONTAMINANT 2982

2024 · Contaminant 2982 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2982

MONITORING · CONTAMINANT 2983

2024 · Contaminant 2983 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2983

MONITORING · CONTAMINANT 2983

2024 · Contaminant 2983 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2983

MONITORING · CONTAMINANT 2984

2024 · Contaminant 2984 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2984

MONITORING · CONTAMINANT 2984

2024 · Contaminant 2984 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2984

MONITORING · CONTAMINANT 2985

2024 · Contaminant 2985 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2985

MONITORING · CONTAMINANT 2985

2024 · Contaminant 2985 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2985

MONITORING · CONTAMINANT 2987

2024 · Contaminant 2987 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2987

MONITORING · CONTAMINANT 2987

2024 · Contaminant 2987 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2987

MONITORING · CONTAMINANT 2989

2024 · Contaminant 2989 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2989

MONITORING · CONTAMINANT 2989

2024 · Contaminant 2989 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2989

MONITORING · CONTAMINANT 2990

2024 · Contaminant 2990 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2990

MONITORING · CONTAMINANT 2990

2024 · Contaminant 2990 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2990

MONITORING · CONTAMINANT 2991

2024 · Contaminant 2991 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2991

MONITORING · CONTAMINANT 2991

2024 · Contaminant 2991 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2991

MONITORING · CONTAMINANT 2992

2024 · Contaminant 2992 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2992

MONITORING · CONTAMINANT 2992

2024 · Contaminant 2992 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2992

MONITORING · CONTAMINANT 2996

2024 · Contaminant 2996 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2996

MONITORING · CONTAMINANT 2996

2024 · Contaminant 2996 · Arsenic Rule

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 2996

MONITORING · CONTAMINANT 4030UNRESOLVED

2024 · Contaminant 4030 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled

CONTAMINANT CODE 4030

MONITORING · CONTAMINANT 4030

2024 · Contaminant 4030 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 4030

MONITORING · CONTAMINANT 4030

2024 · Contaminant 4030 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 4030

MONITORING · CONTAMINANT 4030

2024 · Contaminant 4030 · Phase I/II/V Inorganic Chemical Rules

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 4030

OTHER · CONTAMINANT 7000

2023 · Contaminant 7000 · Phase I/II/V Synthetic Organic Chemical Rules

OTHER; returned to compliance

CONTAMINANT CODE 7000

OTHER · CONTAMINANT 7000

2023 · Contaminant 7000 · Phase I/II/V Synthetic Organic Chemical Rules

OTHER; returned to compliance

CONTAMINANT CODE 7000

OTHER · CONTAMINANT 7000

2023 · Contaminant 7000 · Phase I/II/V Synthetic Organic Chemical Rules

OTHER; returned to compliance

CONTAMINANT CODE 7000

MONITORING · CONTAMINANT 0700

2023 · Contaminant 0700 · Drinking water rule (140)

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 0700

MONITORING · CONTAMINANT 0700

2023 · Contaminant 0700 · Drinking water rule (140)

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 0700

MONITORING · CONTAMINANT 0700

2023 · Contaminant 0700 · Drinking water rule (140)

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 0700

MONITORING · CONTAMINANT 0700

2021 · Contaminant 0700 · Drinking water rule (140)

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 0700

MONITORING · CONTAMINANT 0700

2021 · Contaminant 0700 · Drinking water rule (140)

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 0700

MONITORING · CONTAMINANT 0700

2021 · Contaminant 0700 · Drinking water rule (140)

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 0700

MONITORING · CONTAMINANT 0700

2020 · Contaminant 0700 · Drinking water rule (140)

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 0700

MONITORING · CONTAMINANT 0700

2020 · Contaminant 0700 · Drinking water rule (140)

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 0700

MONITORING · CONTAMINANT 0700

2020 · Contaminant 0700 · Drinking water rule (140)

Failure to monitor as scheduled; returned to compliance

CONTAMINANT CODE 0700

Equity context · ACS 2018-2022 · USEPA-clone EJ disparity

Who Drinks This Water

Horsham, Pennsylvania (Census place; block-group disparity scores aggregated by centroid containment): a service population of 15,683. Local disparity score for pm2.5 (fine particulate) sits below the reference (58). Why we surface this →

POPULATION SHARE
4.4%

Low-income

POPULATION SHARE
30.9%

People of color

POPULATION SHARE
7.3%

Under age 5

POPULATION SHARE
16.1%

Over age 64

NATIONAL PERCENTILE · vs all US block groups (population-weighted; ranked against the national EJScreen indicator distribution)

  • PM2.5 (fine particulate)Health riskFine inhalable particles 2.5 micrometers or smaller. They travel deep into the lungs and into the bloodstream — linked to asthma, heart disease, stroke, and premature death.54near the national median
  • OzoneHealth riskGround-level ozone (smog) inflames the airways. Even short exposures trigger asthma attacks and worsen chronic lung and heart disease.64above the national median
  • Nitrogen dioxide (NO₂)Health riskA tailpipe and combustion gas. Concentrates near busy roads and industrial sites; raises risk of airway inflammation, asthma, and lower respiratory infections in children.35below the national median
  • Diesel particulateHealth riskSoot from diesel engines (trucks, trains, ports, construction). EPA classifies it as a likely human carcinogen and a major driver of childhood asthma near freight corridors.71above the national median
  • Toxic releases (RSEI)Health riskEPA's Risk-Screening Environmental Indicators score — weights TRI chemical releases by toxicity, where they go, and how many people are nearby. Higher means greater modeled cancer and chronic-health risk.71above the national median
  • Traffic proximityHealth riskPopulation-weighted distance to high-volume roads. Living close to heavy traffic raises exposure to PM2.5, NO₂, and diesel exhaust — and the cardiovascular and asthma risks that follow.66above the national median
  • Lead-paint risk (pre-1960 housing)Health riskShare of housing built before 1960, when lead-based paint was common. Dust from deteriorating paint is the leading cause of childhood lead poisoning, which permanently impairs cognitive development.64above the national median
  • Superfund site proximityHealth riskPopulation-weighted distance to NPL Superfund sites — the most contaminated waste sites in the country. Nearby groundwater, soil, and air can carry industrial solvents, metals, and other long-lived contaminants.98in the highest 5% nationally
  • RMP-facility proximityHealth riskDistance to facilities holding chemicals at quantities large enough to require an EPA Risk Management Plan (refineries, fertilizer plants, etc.). These pose acute exposure risk during accidental releases.28below the national median
  • Hazardous-waste site proximityHealth riskDistance to RCRA hazardous-waste handlers (treatment, storage, disposal facilities). Indicates potential exposure to industrial chemicals in air, soil, and groundwater.75above the national median
  • Underground storage tanksHealth riskDensity of underground tanks (gasoline, heating oil, industrial fluids). Leaking tanks are a leading source of benzene and other volatile organic compounds in groundwater drinking-water supplies.79above the national median
  • NPDES wastewater proximityHealth riskDistance to permitted industrial wastewater dischargers. Closer proximity raises exposure to pollutants released into surface waters used for fishing, recreation, and downstream drinking-water intakes.85in the highest 20% nationally
  • Drinking-water non-complianceHealth riskEPA score for public water systems with health-based Safe Drinking Water Act violations. Higher means more residents on systems that recently exceeded safe limits for contaminants like lead, arsenic, or nitrate.89in the highest 20% nationally
EJ disparity scores · service-area block groups (100 = national reference; higher = greater disparate burden)
IndicatorDisparity scoreReading
PM2.5 (fine particulate)58below the reference
Ozone71below the reference
Nitrogen dioxide (NO₂)36well below the reference
Diesel particulate75below the reference
Toxic releases (RSEI)75below the reference
Traffic proximity68below the reference
Lead-paint risk (pre-1960 housing)56below the reference
Superfund site proximity102near the reference
RMP-facility proximity0well below the reference
Hazardous-waste site proximity78below the reference
Underground storage tanks74below the reference
NPDES wastewater proximity88below the reference
Drinking-water non-compliance14well below the reference

Source: Census ACS 2018-2022 (5-year) + USEPA-clone EJ blockgroup stats (raw indicators + EJ disparity mirror).

Source. EPA Safe Drinking Water Information System · retrieved 2026-05-07. Reporting period 2020-01-012026-05-07.

What this is not. SDWIS records compliance against federal MCLs — not a direct readout of tap-water concentrations. Active health-based violations are not the same as a current crisis; we link to the EPA record so you can verify return-to-compliance status before forming a conclusion.