STATE REPORT MD 1 ALERT 229 HEALTH VIOLATIONS

Maryland Water: 1.1K Violations — 615 ZIPs

Name: Water Quality Data for Maryland
Creator: ZipCheckup
Published: 2026-06-03
License: https://creativecommons.org/licenses/by/4.0/

615 ZIP codes · 295 water systems · IPC plumbing code · Updated 2026-06-03

Data: EPA SDWIS, NWS, State plumbing boards, Rewiring America Last verified: 2026-06-03

615

ZIP Codes

295

Water Systems

196

ZIPs with Violations

Active Alerts

IPC

Plumbing Code

C · 61

Avg Safety Score

ZIPs Exceeding Lead Limit

45%

High Radon Risk (Zone 1)

#38

of 51 States

21%

ZIPs Rated A or B

32%

ZIPs with Violations

Maryland average: 61/100 — ranked #38 of 51 states. 6 points below the national average (67). 32% of ZIP codes have recorded violations.

Unlike higher-scoring states, Maryland shows elevated health-based violation rates — compliance shortfalls appear across multiple regions rather than in a single isolated district.

Score Distribution

How Maryland's 615 ZIP codes are distributed across safety grades.

271

211

85-10070-8455-6940-540-39

Home Safety Scores by State

F (0-49) D (50-64) C (65-74) B (75-84) A (85+)

Data: EPA SDWIS, FEMA NFIP, EPA Radon, USGS Earthquake Hazards, NIFC Wildfire • 2026-06-03

Top 10 Safest ZIP Codes in Maryland

Highest Home Safety Scores in the state.

#	ZIP Code	City	County	Score	Grade
1	21606	Easton	Talbot	99	A
2	21610	Betterton	Kent	99	A
3	21623	Church Hill	Queen Anne's	98	A
4	21668	Sudlersville	Queen Anne's	98	A
5	21690	Chestertown	Queen Anne's	98	A
6	21850	Pittsville	Wicomico	98	A
7	21682	Ridgely	Caroline	97	A
8	21683	Ridgely	Caroline	97	A
9	21688	Ridgely	Caroline	97	A
10	21657	Queen Anne	Queen Anne's	95	A

10 Lowest-Scoring ZIP Codes in Maryland

#	ZIP Code	City	County	Score	Grade	Violations
1	21719	Cascade	Washington	32	F	2
2	20859	Potomac	Montgomery	33	F	0
3	21122	Pasadena	Harford	35	F	0
4	20854	Potomac	Montgomery	35	F	0
5	21794	West Friendship	Carroll	40	D	0
6	21790	Tuscarora	Frederick	40	D	0
7	21781	Saint James	Frederick	40	D	0
8	21779	Rohrersville	Washington	40	D	0
9	21778	Rocky Ridge	Frederick	40	D	0
10	21777	Point Of Rocks	Frederick	40	D	0

County Rankings

Water quality breakdown by county. 23 counties with data in Maryland.

Loading county map…

F (0-49) D (50-64) C (65-74) B (75-84) A (85+)

County-level aggregation of ZIP code safety scores • EPA SDWIS, FEMA NFIP, EPA Radon, USGS, NIFC

County	Avg Score	Grade	ZIPs	Best ZIP	Worst ZIP
Prince George's	62	C	46	20709 (83)	20772 (50)
Charles	66	C	19	20640 (83)	20682 (53)
St. Mary's	60	C	26	20636 (82)	20687 (50)
Calvert	47	D	26	20676 (70)	21669 (40)
Anne Arundel	60	C	80	20711 (83)	21222 (45)
Montgomery	52	D	65	20837 (68)	20859 (33)
Howard	62	C	9	21041 (69)	21043 (54)
Queen Anne's	80	B	15	21623 (98)	20736 (65)
Carroll	52	D	34	21048 (70)	21794 (40)
Allegany	66	C	24	21501 (83)	21560 (53)
Baltimore	58	C	73	21057 (68)	20899 (40)
Wicomico	77	B	20	21850 (98)	21804 (59)
Harford	49	D	15	21154 (70)	21122 (35)
Frederick	53	D	35	21773 (70)	21790 (40)
Cecil	63	C	26	21902 (83)	21920 (53)
Talbot	76	B	12	21606 (99)	21671 (60)
Garrett	69	C	8	21520 (82)	21522 (53)
Caroline	82	B	14	21682 (97)	21679 (66)
Kent	77	B	9	21610 (99)	21667 (66)
Dorchester	74	B	13	21664 (95)	21677 (60)
Washington	57	C	20	21783 (70)	21719 (32)
Somerset	57	C	14	21853 (73)	21817 (45)
Worcester	78	B	12	21843 (93)	21838 (60)

Most Common Contaminants in Maryland

Contaminant / Rule	Category	ZIPs Affected	Violations	Health Risk
Stage 2 DBP Rule	Treatment Technique	134	305	Yes
Lead	Inorganic	80	86	No
Consumer Confidence Report Rule	Reporting	79	332	Yes
Total Trihalomethanes (TTHM)	Disinfection Byproducts	73	80	Yes
Lead and Copper Rule	Treatment Technique	53	53	No
Contaminant 2384	Other	50	50	No
Stage 1 DBP Rule	Treatment Technique	44	78	Yes
Surface Water Treatment Rule	Treatment Technique	43	65	No

Overview

We track water quality, weather alerts, plumbing regulations, and energy rebates for 615 ZIP codes across Maryland, covering 295 community water systems that serve approximately 5,212,493 people.

196 of 615 ZIP codes (32%) have recorded EPA violations. 229 health-based violations have been documented.

Active Weather Alerts

1 active alert in Maryland. Severe weather can directly affect tap water quality — flooding, power outages, and infrastructure damage may lead to boil-water advisories.

Alert	Severity	Areas
Coastal Flood Advisory	Minor	Anne Arundel

View all Maryland alerts →

Plumbing Regulations

Maryland follows the International Plumbing Code (2018 edition).

Plumbing code: IPC (2018)
Homeowner DIY: Licensed plumber required
Water heater permit: Required
Annual backflow test: Required

Full Maryland regulations →

Areas with Most Violations

ZIP Code	City	Safety Score	Violations	Health-Based	System
20664	Newburg	B	22	1	Swan Point
21639	Greensboro	A	21	1	Town of Greensboro
21866	Tylerton	C	18	3	Hill Waterworks Cooperative
21903	Perryville	C	15	5	Town of Perryville
21901	North East	C	13	8	Town of North East
21201	Baltimore	C	11	2	City of Baltimore
21202	Baltimore	C	11	2	City of Baltimore
21203	Baltimore	A	11	2	City of Baltimore
21205	Baltimore	C	11	2	City of Baltimore
21206	Baltimore	C	11	2	City of Baltimore

Areas with No Violations

ZIP Code	City	Safety Score	System	Population
20588	Dhs	D	CEDARVILLE MOBILE HOME PARK	780
20606	Abell	C	TOWN OF LEONARDTOWN	5,000
20607	Accokeek	B	Calvert Manor	300
20608	Aquasco	D	THE CALVERTON SCHOOL	461
20609	Avenue	C	TOWN OF LEONARDTOWN	5,000
20610	Barstow	D	PRINCE FREDERICK	4,371
20611	Bel Alton	D	CHARLES COUNTY GARDENS WATER	551
20612	Benedict	D	PRINCE FREDERICK	4,371
20613	Brandywine	B	WASHINGTON SUBURBAN SANITARY COMMISSION	1,900,000
20615	Broomes Island	C	COOK'S TRAILER COURT (AKA GARRETT TP)	120

Home Safety Score

Average Home Safety Score for Maryland: C (61/100)

Lead & Copper

Average lead level (90th percentile): 0.0027 mg/L (EPA action level: 0.015 mg/L)
9 ZIP codes exceed the EPA lead action level

Radon Risk

High risk (Zone 1): 277 ZIP codes (45%)
Moderate risk (Zone 2): 243 ZIP codes
Low risk (Zone 3): 95 ZIP codes

ZIP Code Reports for Maryland

Largest Communities

ZIP Code	City	Population	Safety Grade	Violations
20724	Laurel	2,190,606	B	0
20723	Laurel	2,186,158	C	0
20759	Fulton	2,186,158	D	0
20763	Savage	2,186,158	D	0
20601	Waldorf	1,986,109	B	3
21771	Mount Airy	1,985,205	C	7
20706	Lanham	1,925,000	D	0
20715	Bowie	1,925,000	B	2
20716	Bowie	1,925,000	B	2
20720	Bowie	1,925,000	B	2
20721	Bowie	1,925,000	B	2
20735	Clinton	1,925,000	D	0
20743	Capitol Heights	1,925,000	C	0
20745	Oxon Hill	1,925,000	C	0
20746	Suitland	1,925,000	C	0
20747	District Heights	1,925,000	C	0
20748	Temple Hills	1,925,000	D	0
20762	Andrews Air Force Base	1,925,000	D	0
20769	Glenn Dale	1,925,000	C	0
20772	Upper Marlboro	1,925,000	D	0

Lowest Safety Scores

ZIP Code	City	Score	Grade	Violations
21719	Cascade	32	F	2
20859	Potomac	33	F	0
20854	Potomac	35	F	0
21122	Pasadena	35	F	0
20610	Barstow	40	D	0

Highest Safety Scores

ZIP Code	City	Score	Grade	Violations
21606	Easton	99	A	0
21610	Betterton	99	A	0
21623	Church Hill	98	A	2
21668	Sudlersville	98	A	2
21690	Chestertown	98	A	2

All 615 ZIP Codes in Maryland

20606 (Abell) [C]
21001 (Aberdeen) [C]
21005 (Aberdeen Proving Ground) [D]
21009 (Abingdon) [C] — 2 violations
21520 (Accident) [B] — 2 violations
20607 (Accokeek) [B]
21710 (Adamstown) [D]
21810 (Allen) [C]
20762 (Andrews Air Force Base) [D]
21401 (Annapolis) [B] — 1 violation
21402 (Annapolis) [B] — 1 violation
21403 (Annapolis) [C] — 1 violation
21404 (Annapolis) [B] — 1 violation
21405 (Annapolis) [B] — 1 violation
21409 (Annapolis) [B] — 1 violation
21411 (Annapolis) [B] — 1 violation
21412 (Annapolis) [B] — 1 violation
20701 (Annapolis Junction) [C]
20608 (Aquasco) [D]
21012 (Arnold) [D]
20861 (Ashton) [D]
20609 (Avenue) [C]
21013 (Baldwin) [D]
21201 (Baltimore) [C] — 11 violations ⚠
21202 (Baltimore) [C] — 11 violations ⚠
21203 (Baltimore) [A] — 11 violations ⚠
21205 (Baltimore) [C] — 11 violations ⚠
21206 (Baltimore) [C] — 11 violations ⚠
21209 (Baltimore) [C] — 11 violations ⚠
21210 (Baltimore) [C] — 11 violations ⚠
21211 (Baltimore) [C] — 11 violations ⚠
21212 (Baltimore) [C] — 11 violations ⚠
21213 (Baltimore) [C] — 11 violations ⚠
21214 (Baltimore) [C] — 11 violations ⚠
21215 (Baltimore) [C] — 11 violations ⚠
21216 (Baltimore) [C] — 11 violations ⚠
21217 (Baltimore) [C] — 11 violations ⚠
21218 (Baltimore) [C] — 11 violations ⚠
21223 (Baltimore) [C] — 11 violations ⚠
21224 (Baltimore) [C] — 11 violations ⚠
21229 (Baltimore) [C] — 11 violations ⚠
21230 (Baltimore) [C] — 11 violations ⚠
21231 (Baltimore) [C] — 11 violations ⚠
21233 (Baltimore) [C] — 11 violations ⚠
21235 (Baltimore) [C] — 11 violations ⚠
21239 (Baltimore) [C] — 11 violations ⚠
21240 (Baltimore) [B] — 11 violations ⚠
21241 (Baltimore) [C] — 11 violations ⚠
21250 (Baltimore) [C] — 11 violations ⚠
21251 (Baltimore) [C] — 11 violations ⚠
21260 (Baltimore) [C] — 11 violations ⚠
21263 (Baltimore) [C] — 11 violations ⚠
21264 (Baltimore) [C] — 11 violations ⚠
21265 (Baltimore) [C] — 11 violations ⚠
21268 (Baltimore) [C] — 11 violations ⚠
21270 (Baltimore) [C] — 11 violations ⚠
21273 (Baltimore) [C] — 11 violations ⚠
21274 (Baltimore) [C] — 11 violations ⚠
21275 (Baltimore) [C] — 11 violations ⚠
21278 (Baltimore) [C] — 11 violations ⚠
21279 (Baltimore) [C] — 11 violations ⚠
21280 (Baltimore) [C] — 11 violations ⚠
21281 (Baltimore) [C] — 11 violations ⚠
21282 (Baltimore) [C] — 11 violations ⚠
21283 (Baltimore) [C] — 11 violations ⚠
21284 (Baltimore) [C] — 11 violations ⚠
21285 (Baltimore) [C] — 11 violations ⚠
21287 (Baltimore) [C] — 11 violations ⚠
21288 (Baltimore) [C] — 11 violations ⚠
21289 (Baltimore) [C] — 11 violations ⚠
21290 (Baltimore) [C] — 11 violations ⚠
21297 (Baltimore) [C] — 11 violations ⚠
21298 (Baltimore) [C] — 11 violations ⚠
21607 (Barclay) [C]
20838 (Barnesville) [C]
20610 (Barstow) [D]
21521 (Barton) [C]
20839 (Beallsville) [D]
21014 (Bel Air) [C] — 1 violation
21015 (Bel Air) [C] — 1 violation
20611 (Bel Alton) [D]
21017 (Belcamp) [D]
20704 (Beltsville) [D]
20705 (Beltsville) [D]
20612 (Benedict) [D]
21018 (Benson) [D]
21811 (Berlin) [B] — 1 violation
20810 (Bethesda) [C]
20811 (Bethesda) [C]
20813 (Bethesda) [C]
20814 (Bethesda) [C]
20816 (Bethesda) [C]
20817 (Bethesda) [C]
20824 (Bethesda) [C]
20827 (Bethesda) [C]
20889 (Bethesda) [C]
20892 (Bethesda) [C]
20894 (Bethesda) [C]
21609 (Bethlehem) [C]
21610 (Betterton) [A]
21711 (Big Pool) [D]
21813 (Bishopville) [A] — 2 violations
21522 (Bittinger) [D]
21814 (Bivalve) [C]
20710 (Bladensburg) [D]
21523 (Bloomington) [C]
21713 (Boonsboro) [C] — 5 violations ⚠
21020 (Boring) [D]
20715 (Bowie) [B] — 2 violations ⚠
20716 (Bowie) [B] — 2 violations ⚠
20717 (Bowie) [B] — 2 violations ⚠
20718 (Bowie) [B] — 2 violations ⚠
20719 (Bowie) [B] — 2 violations ⚠
20720 (Bowie) [B] — 2 violations ⚠
20721 (Bowie) [B] — 2 violations ⚠
20841 (Boyds) [B]
21612 (Bozman) [C]
21714 (Braddock Heights) [D]
20613 (Brandywine) [B]
20722 (Brentwood) [D]
20862 (Brinklow) [D]
20833 (Brookeville) [D]
21022 (Brooklandville) [C]
21225 (Brooklyn) [C]
20615 (Broomes Island) [C]
21715 (Brownsville) [D]
21716 (Brunswick) [C] — 2 violations
20616 (Bryans Road) [C]
20617 (Bryantown) [D]
21717 (Buckeystown) [D]
21718 (Burkittsville) [D]
20866 (Burtonsville) [D]
20618 (Bushwood) [C]
21023 (Butler) [D]
20818 (Cabin John) [D]
20619 (California) [D] — 5 violations
20620 (Callaway) [C]
21613 (Cambridge) [B] — 2 violations ⚠
20731 (Capitol Heights) [D]
20743 (Capitol Heights) [C]
20790 (Capitol Heights) [D]
20791 (Capitol Heights) [D]
20799 (Capitol Heights) [C]
21719 (Cascade) [F] — 2 violations ⚠
21228 (Catonsville) [D]
21720 (Cavetown) [D]
21913 (Cecilton) [C] — 7 violations ⚠
21617 (Centreville) [A] — 5 violations ⚠
20621 (Chaptico) [C]
21914 (Charlestown) [C]
20622 (Charlotte Hall) [B] — 5 violations ⚠
21027 (Chase) [D]
20623 (Cheltenham) [C]
20732 (Chesapeake Beach) [C] — 1 violation
21915 (Chesapeake City) [B]
21619 (Chester) [B] — 9 violations ⚠
21620 (Chestertown) [B] — 2 violations ⚠
21690 (Chestertown) [A] — 2 violations ⚠
20815 (Chevy Chase) [D]
20825 (Chevy Chase) [D]
21721 (Chewsville) [D]
21916 (Childs) [B] — 2 violations ⚠
21622 (Church Creek) [C]
21623 (Church Hill) [A] — 2 violations ⚠
20733 (Churchton) [D]
21028 (Churchville) [C]
21624 (Claiborne) [A] — 9 violations ⚠
20871 (Clarksburg) [C] — 7 violations ⚠
21029 (Clarksville) [D]
21722 (Clear Spring) [D]
20624 (Clements) [D]
20735 (Clinton) [D]
20625 (Cobb Island) [C]
21030 (Cockeysville) [D]
20740 (College Park) [D]
20741 (College Park) [D]
20742 (College Park) [D]
21917 (Colora) [D] — 6 violations ⚠
20626 (Coltons Point) [C]
21044 (Columbia) [C] — 6 violations
21045 (Columbia) [C] — 6 violations
21046 (Columbia) [C] — 6 violations
20627 (Compton) [C]
21918 (Conowingo) [C]
21723 (Cooksville) [D]
21625 (Cordova) [C]
21524 (Corriganville) [C]
21626 (Crapo) [C]
21817 (Crisfield) [D]
21627 (Crocheron) [B]
21114 (Crofton) [B]
21032 (Crownsville) [C]
21628 (Crumpton) [B]
21501 (Cumberland) [B]
21502 (Cumberland) [B]
21503 (Cumberland) [B]
21504 (Cumberland) [B]
21505 (Cumberland) [B]
21226 (Curtis Bay) [C]
20872 (Damascus) [B]
20628 (Dameron) [C]
21034 (Darlington) [C] — 8 violations ⚠
21035 (Davidsonville) [C]
21036 (Dayton) [D]
21821 (Deal Island) [D]
20751 (Deale) [D]
21875 (Delmar) [A]
21629 (Denton) [A] — 6 violations ⚠
20855 (Derwood) [D]
20588 (Dhs) [D]
20842 (Dickerson) [D]
20747 (District Heights) [C]
20753 (District Heights) [D]
20629 (Dowell) [D]
20630 (Drayden) [C]
21222 (Dundalk) [D]
20754 (Dunkirk) [C] — 1 violation
21919 (Earleville) [B] — 2 violations ⚠
21631 (East New Market) [A] — 1 violation
21601 (Easton) [A]
21606 (Easton) [A]
21528 (Eckhart Mines) [D]
21822 (Eden) [C]
21037 (Edgewater) [D]
21040 (Edgewood) [D]
21920 (Elk Mills) [D]
21075 (Elkridge) [C]
21921 (Elkton) [C] — 7 violations ⚠
21922 (Elkton) [B] — 7 violations ⚠
21529 (Ellerslie) [C]
21041 (Ellicott City) [C] — 5 violations ⚠
21042 (Ellicott City) [C] — 5 violations ⚠
21043 (Ellicott City) [D] — 5 violations ⚠
21727 (Emmitsburg) [C] — 5 violations
21221 (Essex) [D]
21824 (Ewell) [C]
21733 (Fairplay) [D]
21047 (Fallston) [C]
20632 (Faulkner) [D]
21632 (Federalsburg) [A] — 9 violations ⚠
21048 (Finksburg) [B]
21634 (Fishing Creek) [D]
21530 (Flintstone) [C]
21050 (Forest Hill) [C]
21051 (Fork) [C]
20755 (Fort George G Meade) [D]
21052 (Fort Howard) [C]
20744 (Fort Washington) [D]
20749 (Fort Washington) [D]
21701 (Frederick) [C] — 3 violations ⚠
21702 (Frederick) [C] — 3 violations ⚠
21703 (Frederick) [C] — 3 violations ⚠
21704 (Frederick) [C] — 3 violations ⚠
21705 (Frederick) [C] — 3 violations ⚠
21709 (Frederick) [C] — 3 violations ⚠
21053 (Freeland) [C] — 5 violations ⚠
20758 (Friendship) [D]
21531 (Friendsville) [C]
21532 (Frostburg) [C]
21826 (Fruitland) [A] — 2 violations
20759 (Fulton) [D]
21734 (Funkstown) [C]
20877 (Gaithersburg) [D]
20878 (Gaithersburg) [D]
20879 (Gaithersburg) [D]
20882 (Gaithersburg) [D]
20883 (Gaithersburg) [D]
20884 (Gaithersburg) [D]
20885 (Gaithersburg) [D]
20898 (Gaithersburg) [D]
20899 (Gaithersburg) [D]
21635 (Galena) [C]
20765 (Galesville) [C]
21054 (Gambrills) [B] — 3 violations ⚠
20896 (Garrett Park) [D]
21930 (Georgetown) [C]
20874 (Germantown) [D]
20875 (Germantown) [D]
20876 (Germantown) [D]
21056 (Gibson Island) [C]
21829 (Girdletree) [B]
21057 (Glen Arm) [C] — 8 violations ⚠
21060 (Glen Burnie) [C]
21061 (Glen Burnie) [C]
21062 (Glen Burnie) [D]
20812 (Glen Echo) [D]
21737 (Glenelg) [D]
20769 (Glenn Dale) [C]
21738 (Glenwood) [D]
21071 (Glyndon) [D]
21636 (Goldsboro) [C]
21536 (Grantsville) [B]
21638 (Grasonville) [B] — 4 violations ⚠
20634 (Great Mills) [C]
20768 (Greenbelt) [D]
20770 (Greenbelt) [D]
20771 (Greenbelt) [D]
21639 (Greensboro) [A] — 21 violations ⚠
21010 (Gunpowder) [D]
21207 (Gwynn Oak) [D]
21740 (Hagerstown) [C] — 1 violation
21741 (Hagerstown) [C] — 1 violation
21742 (Hagerstown) [C] — 1 violation
21746 (Hagerstown) [C] — 1 violation
21747 (Hagerstown) [C] — 1 violation
21748 (Hagerstown) [C] — 1 violation
21749 (Hagerstown) [C] — 1 violation
21227 (Halethorpe) [D]
21074 (Hampstead) [C]
21750 (Hancock) [C] — 2 violations
21076 (Hanover) [C]
21077 (Harmans) [C]
20776 (Harwood) [C]
21078 (Havre De Grace) [C] — 7 violations ⚠
21830 (Hebron) [A]
20635 (Helen) [D]
21640 (Henderson) [B]
20777 (Highland) [D]
21641 (Hillsboro) [B]
20636 (Hollywood) [B] — 2 violations
20637 (Hughesville) [C]
21031 (Hunt Valley) [D]
21065 (Hunt Valley) [D]
20639 (Huntingtown) [D] — 7 violations ⚠
21643 (Hurlock) [A] — 2 violations ⚠
20781 (Hyattsville) [D]
20782 (Hyattsville) [D]
20783 (Hyattsville) [D]
20784 (Hyattsville) [C]
20785 (Hyattsville) [C]
20787 (Hyattsville) [D]
20788 (Hyattsville) [D]
21082 (Hydes) [D]
21754 (Ijamsville) [D]
20640 (Indian Head) [B] — 1 violation
21644 (Ingleside) [C]
20643 (Ironsides) [D]
20645 (Issue) [C]
21084 (Jarrettsville) [C]
21755 (Jefferson) [D]
20794 (Jessup) [C] — 6 violations ⚠
21085 (Joppa) [D]
21756 (Keedysville) [D]
21645 (Kennedyville) [A] — 1 violation ⚠
20891 (Kensington) [D]
20895 (Kensington) [D]
21757 (Keymar) [D]
21087 (Kingsville) [C]
21538 (Kitzmiller) [C]
21758 (Knoxville) [D]
20646 (La Plata) [B] — 2 violations
21759 (Ladiesburg) [D]
20703 (Lanham) [D]
20706 (Lanham) [D]
20707 (Laurel) [B]
20708 (Laurel) [B]
20709 (Laurel) [B]
20723 (Laurel) [C]
20724 (Laurel) [B]
20725 (Laurel) [B]
20726 (Laurel) [B]
20650 (Leonardtown) [B] — 6 violations ⚠
20653 (Lexington Park) [B] — 3 violations ⚠
21762 (Libertytown) [D]
21088 (Lineboro) [D]
21835 (Linkwood) [C]
21090 (Linthicum Heights) [B] — 3 violations ⚠
21765 (Lisbon) [D]
21766 (Little Orleans) [D]
21539 (Lonaconing) [B] — 5 violations ⚠
21092 (Long Green) [D]
20711 (Lothian) [B]
20656 (Loveville) [D]
21540 (Luke) [B] — 1 violation
20657 (Lusby) [D] — 5 violations ⚠
21093 (Lutherville Timonium) [D]
21094 (Lutherville Timonium) [C]
21648 (Madison) [C]
21102 (Manchester) [B]
21836 (Manokin) [D]
20658 (Marbury) [B] — 5 violations ⚠
21837 (Mardela Springs) [B]
21838 (Marion Station) [C]
21104 (Marriottsville) [D]
21649 (Marydel) [C]
21105 (Maryland Line) [C]
21650 (Massey) [C]
21767 (Maugansville) [D]
21106 (Mayo) [D]
21541 (Mc Henry) [C]
21647 (Mcdaniel) [B]
20659 (Mechanicsville) [C]
21220 (Middle River) [D]
21769 (Middletown) [C] — 2 violations ⚠
21542 (Midland) [C]
21543 (Midlothian) [B] — 2 violations ⚠
21108 (Millersville) [B] — 5 violations ⚠
21651 (Millington) [A] — 2 violations
21111 (Monkton) [C]
21770 (Monrovia) [D]
20886 (Montgomery Village) [D]
20660 (Morganza) [D]
21771 (Mount Airy) [C] — 7 violations ⚠
20712 (Mount Rainier) [D]
21545 (Mount Savage) [C]
20661 (Mount Victoria) [D]
21773 (Myersville) [B]
20662 (Nanjemoy) [C]
21840 (Nanticoke) [C]
21652 (Neavitt) [C]
21774 (New Market) [D]
21775 (New Midway) [D]
21776 (New Windsor) [B]
21841 (Newark) [A] — 4 violations
20664 (Newburg) [B] — 22 violations ⚠
21653 (Newcomb) [C]
20714 (North Beach) [D] — 3 violations ⚠
21901 (North East) [C] — 13 violations ⚠
21236 (Nottingham) [C]
21550 (Oakland) [B]
21842 (Ocean City) [B] — 11 violations ⚠
21843 (Ocean City) [A] — 11 violations ⚠
21113 (Odenton) [C]
21555 (Oldtown) [C]
20830 (Olney) [D]
20832 (Olney) [D]
20736 (Owings) [C]
21117 (Owings Mills) [D]
21654 (Oxford) [B] — 4 violations ⚠
20745 (Oxon Hill) [C]
20750 (Oxon Hill) [D]
20667 (Park Hall) [C]
21120 (Parkton) [C]
21234 (Parkville) [C]
21849 (Parsonsburg) [A] — 2 violations ⚠
21122 (Pasadena) [F]
21123 (Pasadena) [D]
20670 (Patuxent River) [B] — 3 violations
21128 (Perry Hall) [C]
21902 (Perry Point) [B]
21130 (Perryman) [D]
21903 (Perryville) [C] — 15 violations ⚠
21131 (Phoenix) [C]
21208 (Pikesville) [D]
20674 (Piney Point) [D]
21556 (Pinto) [D]
21850 (Pittsville) [A] — 3 violations
21851 (Pocomoke City) [A] — 6 violations ⚠
21777 (Point Of Rocks) [D]
20675 (Pomfret) [D]
20837 (Poolesville) [C] — 2 violations
21904 (Port Deposit) [C] — 9 violations
20676 (Port Republic) [B] — 1 violation
20677 (Port Tobacco) [D]
20854 (Potomac) [F]
20859 (Potomac) [F]
21852 (Powellville) [C]
21655 (Preston) [A] — 3 violations ⚠
21656 (Price) [C]
20678 (Prince Frederick) [C] — 1 violation
21853 (Princess Anne) [B]
21132 (Pylesville) [C]
21856 (Quantico) [C]
21657 (Queen Anne) [A]
21658 (Queenstown) [B] — 6 violations
21133 (Randallstown) [C]
21557 (Rawlings) [B] — 2 violations ⚠
21857 (Rehobeth) [C]
21136 (Reisterstown) [D]
21659 (Rhodesdale) [B]
21139 (Riderwood) [C]
20680 (Ridge) [C]
21660 (Ridgely) [A] — 5 violations
21682 (Ridgely) [A] — 5 violations
21683 (Ridgely) [A] — 5 violations
21688 (Ridgely) [A] — 5 violations
21911 (Rising Sun) [B] — 2 violations ⚠
21140 (Riva) [C]
20737 (Riverdale) [D]
20738 (Riverdale) [D]
21661 (Rock Hall) [B] — 1 violation
20682 (Rock Point) [D]
20847 (Rockville) [D]
20848 (Rockville) [D]
20849 (Rockville) [D]
20850 (Rockville) [D]
20851 (Rockville) [D]
20852 (Rockville) [D]
20853 (Rockville) [D]
20857 (Rockville) [D]
21778 (Rocky Ridge) [D]
21779 (Rohrersville) [D]
21237 (Rosedale) [C]
21662 (Royal Oak) [C]
21780 (Sabillasville) [C]
20684 (Saint Inigoes) [C]
21781 (Saint James) [D]
20685 (Saint Leonard) [D]
20686 (Saint Marys City) [C]
21663 (Saint Michaels) [C]
21801 (Salisbury) [C] — 4 violations ⚠
21802 (Salisbury) [C] — 4 violations ⚠
21803 (Salisbury) [C] — 4 violations ⚠
21804 (Salisbury) [C] — 4 violations ⚠
20860 (Sandy Spring) [D]
20763 (Savage) [D]
20687 (Scotland) [D]
21664 (Secretary) [A]
21144 (Severn) [B] — 2 violations ⚠
21146 (Severna Park) [B] — 3 violations ⚠
20764 (Shady Side) [D]
21782 (Sharpsburg) [C]
21861 (Sharptown) [A] — 3 violations ⚠
21665 (Sherwood) [C]
21862 (Showell) [B]
20901 (Silver Spring) [C]
20902 (Silver Spring) [D]
20903 (Silver Spring) [C]
20904 (Silver Spring) [C]
20905 (Silver Spring) [C]
20906 (Silver Spring) [D]
20907 (Silver Spring) [C]
20908 (Silver Spring) [C]
20910 (Silver Spring) [C]
20911 (Silver Spring) [C]
20914 (Silver Spring) [C]
20915 (Silver Spring) [C]
20916 (Silver Spring) [C]
20918 (Silver Spring) [C]
20993 (Silver Spring) [C]
20997 (Silver Spring) [C]
21150 (Simpsonville) [D]
21783 (Smithsburg) [B] — 1 violation
21863 (Snow Hill) [A] — 2 violations ⚠
20688 (Solomons) [D]
20697 (Southern Md Facility) [D]
20797 (Southern Md Facility) [D]
21152 (Sparks Glencoe) [C]
21219 (Sparrows Point) [D]
20868 (Spencerville) [D]
21560 (Spring Gap) [D]
21153 (Stevenson) [C] — 4 violations ⚠
21666 (Stevensville) [C] — 5 violations
21667 (Still Pond) [C]
21864 (Stockton) [C]
21154 (Street) [B] — 1 violation
20897 (Suburb Maryland Fac) [D]
21668 (Sudlersville) [A] — 2 violations
20746 (Suitland) [C]
20752 (Suitland) [D]
20689 (Sunderland) [C] — 2 violations ⚠
21561 (Swanton) [B] — 2 violations ⚠
21784 (Sykesville) [C] — 8 violations ⚠
20912 (Takoma Park) [D]
20913 (Takoma Park) [D]
20690 (Tall Timbers) [C]
21787 (Taneytown) [C]
21669 (Taylors Island) [D]
20748 (Temple Hills) [D]
20757 (Temple Hills) [D]
21670 (Templeville) [C]
21788 (Thurmont) [C]
21671 (Tilghman) [C]
21672 (Toddville) [C]
21204 (Towson) [D]
21252 (Towson) [D]
21286 (Towson) [C]
20779 (Tracys Landing) [C]
21673 (Trappe) [C]
21790 (Tuscarora) [D]
21865 (Tyaskin) [C]
21866 (Tylerton) [C] — 18 violations ⚠
21791 (Union Bridge) [B]
21792 (Unionville) [D]
21867 (Upper Fairmount) [C]
21156 (Upper Falls) [D]
20772 (Upper Marlboro) [D]
20773 (Upper Marlboro) [D]
20774 (Upper Marlboro) [C]
20775 (Upper Marlboro) [D]
20792 (Upper Marlboro) [D]
21155 (Upperco) [D]
20692 (Valley Lee) [C]
21869 (Vienna) [A]
20601 (Waldorf) [B] — 3 violations
20602 (Waldorf) [B] — 3 violations
20603 (Waldorf) [B] — 3 violations
20604 (Waldorf) [B] — 3 violations
21793 (Walkersville) [C] — 1 violation
21912 (Warwick) [D]
20880 (Washington Grove) [D]
20693 (Welcome) [D]
21794 (West Friendship) [D]
20778 (West River) [C]
21562 (Westernport) [C] — 5 violations ⚠
21157 (Westminster) [C] — 5 violations ⚠
21158 (Westminster) [C] — 5 violations ⚠
21871 (Westover) [D]
21890 (Westover) [D]
21872 (Whaleyville) [C]
21161 (White Hall) [B]
21162 (White Marsh) [C]
20695 (White Plains) [D]
21160 (Whiteford) [D]
21874 (Willards) [A] — 5 violations ⚠
21795 (Williamsport) [C] — 6 violations ⚠
21244 (Windsor Mill) [C]
21675 (Wingate) [C]
21676 (Wittman) [C]
21797 (Woodbine) [D]
21798 (Woodsboro) [C] — 6 violations
21163 (Woodstock) [D]
21677 (Woolford) [C]
21678 (Worton) [B]
21679 (Wye Mills) [C]

Data Sources

Water quality: EPA Safe Drinking Water Information System (SDWIS)
Weather alerts: National Weather Service (NWS)
Regulations: State plumbing boards, ICC, IAPMO

Updated daily.

Frequently Asked Questions

Is the water safe to drink in Maryland?

Maryland has 295 community water systems serving 5,212,493 people across 615 ZIP codes. There are 1,135 recorded violations, including 229 health-based. 196 of 615 ZIP codes have at least one violation.

What plumbing code does Maryland follow?

Maryland follows the IPC plumbing code. A licensed plumber is generally required for plumbing work.

Is lead a concern in Maryland's drinking water?

9 ZIP codes in Maryland have lead levels exceeding the EPA action level of 0.015 mg/L.

What is the radon risk in Maryland?

45% of ZIP codes in Maryland fall in EPA Radon Zone 1 (highest risk).