Chromium-6 Contamination

Chromium-6 in Pennsylvania Drinking Water

Ranked by max chromium-6 detected (µg/L) · UCMR 3 data (2013–2015) · Data from EPA SDWIS & UCMR

120

Cities Tested

120

Detected

100%

% Detected

0.46 µg/L

State Avg

▼ 0% vs national

vs National

487

Health Violations

Analysis

Chromium-6 in Pennsylvania: what the data shows

Pennsylvania has 120 cities with chromium-6 data from the EPA's UCMR 3 program (2013–2015). Hexavalent chromium (Cr VI) was detected in 120 of those cities. There is currently no federal MCL for chromium-6 — California's 10 µg/L limit is used as a reference. The state average max detected level is 0.46 µg/L. Chromium-6 occurs naturally in some groundwater aquifers but also from industrial discharge, particularly from steel processing, chrome plating, and leather tanning. It is distinct from trivalent chromium (Cr III), which is an essential nutrient at low doses. The National Toxicology Program and IARC classify chromium-6 as a carcinogen via inhalation; the evidence for drinking water carcinogenicity is strong but regulatory action at the federal level remains pending as of 2026. Reverse osmosis systems effectively remove chromium-6 to near-undetectable levels.

Comparison

Cities exceeding No federal MCL (CA: 10 µg/L)

Pennsylvania

100%

120 of 120 cities

← = Exactly at national rate

National avg

100%

4005 of 4005 cities

City Map

Chromium-6 data across Pennsylvania

Each dot is a city with UCMR 3 chromium-6 data. Detected cities are shown; there is no federal MCL — California's 10 µg/L limit is used as a reference. Size reflects population served.

Worst Offenders

Top 10 cities by chromium-6 level in Pennsylvania

Highest Chromium-6 levels (µg/L)

All Cities

All Pennsylvania cities ranked by chromium-6 level

#	City	Level	Detected?	Violations	Grade
1	North Wales	11.59 µg/L	Detected	22	F
2	Reading	3.29 µg/L	Detected	91	F
3	Bryn Mawr	2.60 µg/L	Detected	36	F
4	Morrisville	2.30 µg/L	Detected	39	D
5	New Castle	2.07 µg/L	Detected	12	F
6	Norristown	1.90 µg/L	Detected	23	F
7	Hummelstown	1.53 µg/L	Detected	35	C+
8	Lansdale	1.20 µg/L	Detected	22	F
9	Spring City	1.12 µg/L	Detected	2	B+
10	Sellersville	1.00 µg/L	Detected	9	F
11	Allentown	0.91 µg/L	Detected	66	F
12	Allison Park	0.87 µg/L	Detected	0	A
13	Mechanicsburg	0.80 µg/L	Detected	13	F
14	Elizabethtown	0.78 µg/L	Detected	87	F
15	Warrington	0.77 µg/L	Detected	34	F
16	Philadelphia	0.75 µg/L	Detected	14	B
17	Mcmurray	0.73 µg/L	Detected	2	A-
18	Pittsburgh	0.72 µg/L	Detected	44	F
19	Levittown	0.68 µg/L	Detected	4	B
20	Doylestown	0.68 µg/L	Detected	4	D
21	Oakdale	0.65 µg/L	Detected	12	C-
22	Scranton	0.60 µg/L	Detected	15	F
23	State College	0.60 µg/L	Detected	3	D
24	Fairless Hills	0.60 µg/L	Detected	15	D+
25	Newtown	0.60 µg/L	Detected	25	F
26	Boiling Springs	0.53 µg/L	Detected	5	C+
27	Mount Joy	0.49 µg/L	Detected	8	B+
28	Aliquippa	0.48 µg/L	Detected	9	F
29	Ambler	0.45 µg/L	Detected	4	F
30	Quakertown	0.41 µg/L	Detected	12	F
31	Southampton	0.39 µg/L	Detected	9	D
32	Blandon	0.39 µg/L	Detected	0	B+
33	Pottstown	0.38 µg/L	Detected	29	F
34	University Park	0.38 µg/L	Detected	0	C
35	Jamison	0.36 µg/L	Detected	1	B+
36	Harrisburg	0.35 µg/L	Detected	26	F
37	Phoenixville	0.35 µg/L	Detected	13	C
38	Lancaster	0.34 µg/L	Detected	68	F
39	Altoona	0.33 µg/L	Detected	64	F
40	Emmaus	0.33 µg/L	Detected	16	C+
41	Ephrata	0.32 µg/L	Detected	21	C
42	Whitehall	0.31 µg/L	Detected	32	B+
43	Warminster	0.30 µg/L	Detected	1	D
44	Coatesville	0.29 µg/L	Detected	61	F
45	Shippensburg	0.28 µg/L	Detected	11	D
46	Richboro	0.27 µg/L	Detected	2	F
47	Horsham	0.27 µg/L	Detected	1	F
48	Landisville	0.26 µg/L	Detected	2	B-
49	Shamokin	0.24 µg/L	Detected	18	F
50	Dover	0.24 µg/L	Detected	16	F
51	Tobyhanna	0.24 µg/L	Detected	10	F
52	Gettysburg	0.23 µg/L	Detected	37	F
53	Chambersburg	0.22 µg/L	Detected	49	F
54	Milton	0.22 µg/L	Detected	15	F
55	Carlisle	0.22 µg/L	Detected	13	F
56	Lititz	0.21 µg/L	Detected	73	F
57	Williamsport	0.19 µg/L	Detected	19	F
58	Saint Marys	0.19 µg/L	Detected	10	B-
59	South Heights	0.19 µg/L	Detected	1	A-
60	Easton	0.17 µg/L	Detected	37	F
61	Northampton	0.17 µg/L	Detected	45	F
62	Montoursville	0.17 µg/L	Detected	10	F
63	Adrian	0.17 µg/L	Detected	3	B+
64	Wilkes Barre	0.16 µg/L	Detected	2	B+
65	Chester	0.16 µg/L	Detected	0	B
66	Yardley	0.16 µg/L	Detected	1	B+
67	St Thomas	0.16 µg/L	Detected	6	B
68	Clarks Summit	0.15 µg/L	Detected	6	C-
69	Milroy	0.13 µg/L	Detected	2	B
70	Sayre	0.13 µg/L	Detected	6	C-
71	Windber	0.13 µg/L	Detected	0	B-
72	Kutztown	0.12 µg/L	Detected	21	F
73	Sharon	0.12 µg/L	Detected	26	F
74	Cranberry Twp	0.12 µg/L	Detected	2	B+
75	Erie	0.11 µg/L	Detected	35	D
76	York	0.11 µg/L	Detected	34	F
77	Johnstown	0.11 µg/L	Detected	55	D
78	Beaver Falls	0.11 µg/L	Detected	22	F
79	Bradford	0.11 µg/L	Detected	6	C+
80	Mc Connellstown	0.11 µg/L	Detected	0	B
81	Greensburg	0.10 µg/L	Detected	19	D
82	Sarver	0.10 µg/L	Detected	9	C+
83	Birdsboro	0.10 µg/L	Detected	15	C
84	Columbia	0.09 µg/L	Detected	46	F
85	Monroeville	0.09 µg/L	Detected	4	A
86	Pottsville	0.09 µg/L	Detected	13	C-
87	Uniontown	0.09 µg/L	Detected	0	A-
88	Warren	0.09 µg/L	Detected	7	D
89	Ambridge	0.09 µg/L	Detected	19	F
90	East Stroudsburg	0.08 µg/L	Detected	74	F
91	Jefferson	0.08 µg/L	Detected	2	A-
92	Oil City	0.08 µg/L	Detected	2	A
93	Moon Township	0.08 µg/L	Detected	1	B
94	Wilkinsburg	0.08 µg/L	Detected	6	B
95	Bethlehem	0.08 µg/L	Detected	29	F
96	Franklin	0.08 µg/L	Detected	12	F
97	Sunbury	0.08 µg/L	Detected	6	C-
98	Huntingdon	0.08 µg/L	Detected	14	B-
99	East Greenville	0.08 µg/L	Detected	9	F
100	White Haven	0.07 µg/L	Detected	44	F
101	Dallastown	0.07 µg/L	Detected	3	B+
102	Portland	0.07 µg/L	Detected	5	B
103	Matamoras	0.07 µg/L	Detected	1	D
104	Danville	0.07 µg/L	Detected	3	D
105	Dunbar	0.06 µg/L	Detected	12	B+
106	Hazleton	0.06 µg/L	Detected	6	D+
107	Philipsburg	0.06 µg/L	Detected	1	C
108	Waynesboro	0.06 µg/L	Detected	7	D
109	Natrona Heights	0.06 µg/L	Detected	12	B-
110	Clearfield	0.06 µg/L	Detected	3	A-
111	Blairsville	0.06 µg/L	Detected	22	F
112	Oakmont	0.05 µg/L	Detected	0	A
113	Charleroi	0.05 µg/L	Detected	25	C-
114	Lebanon	0.05 µg/L	Detected	8	F
115	Hanover	0.05 µg/L	Detected	6	B
116	New Kensington	0.05 µg/L	Detected	0	A
117	Tunkhannock	0.04 µg/L	Detected	21	F
118	Bloomsburg	0.03 µg/L	Detected	6	F
119	Latrobe	0.03 µg/L	Detected	4	B-
120	Mcmurry	0.03 µg/L	Detected	3	A

FAQ

Frequently asked questions about chromium-6 in Pennsylvania

Is chromium-6 in Pennsylvania tap water dangerous?

Chromium-6 (hexavalent chromium) is a potential human carcinogen. There is currently no federal MCL — California's 10 µg/L limit is the most protective US standard. 120 cities in Pennsylvania had detectable chromium-6 in UCMR 3 testing (2013–2015). Reverse osmosis is the most effective removal method.

Where does chromium-6 come from in Pennsylvania water?

Chromium-6 enters water supplies from two main sources: natural weathering of chromium-containing rock formations (especially in the Southwest and parts of the Midwest) and industrial discharge from steel mills, chrome plating, and coal ash sites. Groundwater systems are more commonly affected by natural sources, while surface water systems near industrial areas face pollution-related risks.

How can I filter chromium-6 from my water in Pennsylvania?

Reverse osmosis (RO) systems are the most effective, removing over 95% of chromium-6. Some high-quality activated alumina or anion exchange filters also provide significant reduction. Standard carbon filters and pitcher filters are generally NOT effective against chromium-6. Look for filters certified by NSF International against NSF/ANSI 58 (for RO systems).

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