EPA SDWIS DataMaryland

Total Coliform Bacteria in Maryland Drinking Water

Maryland has 7,992 public water systems. 3891 have recorded total coliform bacteria violations.

Total Systems

7,992

With Violations

3,891

EPA MCL

N/A

Population Served

6.0M

Total Coliform Bacteria in Maryland: Key Facts

Total Water Systems

7,992

Systems with Violations

3,891

Lead Violations

56

Copper Violations

305

EPA Standard

Zero tolerance (presence/absence test)

MCLG (goal): 0 mg/L

Water Systems with Violations in Maryland

Health Effects of Total Coliform Bacteria Exposure

Indicator organism

Presence indicates possible fecal contamination

Pathogen risk

May accompany E. coli, Giardia, and other pathogens

GI illness

Can cause nausea, cramps, and diarrhea

Not harmful themselves but indicate possible presence of harmful pathogens. E. coli indicates recent fecal contamination.

Frequently Asked Questions

Is there total coliform bacteria in Maryland water?

Maryland has 7,992 public water systems. 3891 have recorded total coliform bacteria violations based on EPA SDWIS data. If you are on a private well, your water is not covered by these regulations and should be tested independently.

How can I check my Maryland water for total coliform bacteria?

Search for your water system using the WaterCheck system lookup, or contact your utility and request a copy of your Consumer Confidence Report (CCR). The CCR is published annually and lists all detected contaminants, their levels, and the EPA MCLs. For private wells, contact a state-certified lab for independent testing.

What is the EPA limit for total coliform bacteria?

The EPA Maximum Contaminant Level (MCL) for total coliform bacteria is Zero tolerance (presence/absence test). Systems that exceed MCLs are required to notify customers and take corrective action.

Total Coliform Bacteria at a Glance

Categorymicrobial
EPA MCLZero tolerance (presence/absence test)

Source

Naturally present in the environment; fecal contamination from human or animal waste

How to Filter Total Coliform Bacteria

  • +Boiling water for 1 minute kills coliform bacteria
  • +NSF/ANSI 55 certified UV systems eliminate bacteria
  • +Contact your water utility immediately if coliform is detected