Water in Maryland.
Maryland's Chesapeake watershed and Potomac source water carry agricultural and urban runoff. Baltimore's aging service lines and PFAS contamination from military and industrial sites are documented concerns.
How Maryland regulates drinking water.
Federal SDWA primacy. State PFAS Action Plan launched 2020. Active Chesapeake watershed protection.
Maryland Department of the Environment — Water Supply Program
Maryland's water history, in order.
The contamination events, regulatory shifts, and major settlements that define how this state thinks about drinking water today.
- 2017
PFAS contamination at Joint Base Andrews triggers Prince George's County response.
- 2020
Maryland PFAS Action Plan launched with statewide sampling.
The actual water you drink.
The physical rivers, aquifers, lakes, and reservoirs that feed Maryland's public water systems. Source quality is the foundation of tap quality — and where the long-term protection fights happen.
- riverPatuxent + Patapsco Rivers
Baltimore metro.
- riverPotomac River
DC + Montgomery / Prince George's.
- aquiferCoastal Plain Aquifer System
Eastern Shore.
Source-water mix
~70% surface water, ~30% groundwater
Major cities served
Baltimore · Frederick · Rockville · Gaithersburg · Annapolis
Who actually serves the water.
The largest public water systems in Maryland by population served. Click your ZIP after to see the full live EWG report for your specific utility.
- Baltimore City Department of Public WorksBaltimore1,800Kserved
- Washington Suburban Sanitary CommissionDC metro / MD1,900Kserved
Where the contamination comes from.
Every state has a different industrial fingerprint. The industries below are the dominant historical and active contamination sources in Maryland's drinking water systems.
Joint Base Andrews and Patuxent Naval Air Station PFAS contamination documented. Baltimore industrial legacy drives chromium and chlorinated-solvent contamination. Poultry CAFO operations on Eastern Shore drive nitrate exposure.
What state data flags most consistently.
Drawn from EPA SDWIS sampling records, EWG state summaries, and regional regulatory action over the past five years. Read the full deep dive on each.
PFAS (Forever Chemicals)
A class of ~15,000 synthetic chemicals that don't break down. Now regulated for the first time.
Trihalomethanes (TTHMs)
Byproducts of chlorinating water. Linked to bladder cancer at chronic exposure.
Lead
A neurotoxic metal that leaches from old pipes and solder. No safe level for children.
Chromium-6 (Hexavalent Chromium)
The Erin Brockovich chemical. A known carcinogen with no federal-specific limit yet.
Risk isn't evenly distributed.
Baltimore residents in pre-1986 housing face significant lead exposure. Eastern Shore agricultural communities face nitrate and PFAS.
~20% on private wells, mostly in Eastern Shore agricultural counties.
What's coming for Maryland's water.
Chesapeake Bay sea-level rise threatens Eastern Shore wellfields. Increasing intense rainfall overwhelms Baltimore combined sewer system, affecting Patapsco intake quality. Higher summer temperatures increase Chesapeake harmful algal blooms.
Statewide mandate
Maryland HB 270 (2017) requires lead testing in all public schools. Results published on the MD State Department of Education site.
Five questions for your next Consumer Confidence Report.
Your utility is required to send you a Consumer Confidence Report annually. Most are dense and procedural. These are the questions worth following up on for Maryland specifically.
- 1
Has my school posted current HB 270 lead test results?
- 2
Does my Eastern Shore well face saltwater intrusion risk?
- 3
Has my Prince George's County system been impacted by Joint Base Andrews PFAS?
Most state regulators allow public records requests for the underlying lab reports behind your CCR — your utility should be able to provide them on request.
What's changed in Maryland water law.
Drinking water regulation moves at the state level as much as the federal level. Below are notable recent bills and regulatory actions specific to Maryland.
- 2022
MD PFAS Restriction Act — bans PFAS in firefighting foam, food packaging, cosmetics.
For Baltimore lead: NSF/ANSI 53 carbon block. For Eastern Shore private wells: NSF/ANSI 58 reverse osmosis.
We don't recommend brands — the NSF/ANSI certification number matters more than the name on the box.
This is the state. Your address is the answer.
State-level patterns don't tell you about your specific tap. Run your ZIP for the live EWG contaminant report on your utility — or build a personalized Water File for your household.
Source-water mix, utility counts, lead-service-line estimates, and private-well shares are approximate, drawn from EPA SDWIS public data and state primacy-agency summaries. Contaminant rankings reflect EWG state-level monitoring data and regional regulatory action — they are not exhaustive. Timeline events are publicly documented. See methodology for the full sourcing. Search EPA SDWIS for Maryland