Tapcensus

Maryland

St. Mary's County drinking water quality

202 active public water systems serve 125,704 people in St. Mary's County. 156 are compliant, 46 had at least one EPA violation in the past three years, 0 are designated serious violators, and 0 carry a health flag.

Active systems 202 38 community systems
People served 126K by public water systems
Systems with violations 46 23% of active systems, past 3 years
Serious violators 0 0 systems carry a health flag

Community water systems

38 systems, largest first
SystemServesStatusRules violated, 3 yrUnresolved
Lexington Park
 43,030 3 0
Patuxent Naval Air Station (navfac-Wash)
 22,000 1 0
Town of Leonardtown
 5,000 1 0
Country Lakes
 3,016 1 0
Cedar Cove
 2,728 1 0
Saint Marys College
 2,200 1 0
Wicomico Shores
 1,262 1 0
Greenbrier
 1,161 1 0
Breton Bay
 1,012 2 0
Lord Calvert Trailer Park
 892 1 0
Hunting Quarters
 715 1 0
Rolling Acres
 699 1 0
Piney Point
 672 1 0
St. Clements Shores
 620 1 0
Charlotte Hall
 615 1 0
Forrest Farm Subdivision
 577 1 0
Laurel Ridge
 560 1 0
Persimmon Hills
 514 1 0
Wilderness Run
 511 2 0
Lexington Estates
 300 0 0
Birch Manor
 272 1 0
Charlotte Hall VA Home
 270 1 0
Grandview Haven
 269 1 0
Piney Point Landings
 239 1 0
Villages at Leonardtown
 239 1 0
Fenwick Manor
 234 1 0
Leonardtown Farm
 193 1 0
Southgate
 188 1 0
Langley Mobile Home Park
 175 2 0
King & Kennedy
 169 1 0
Mount Pleasant Water Co., Inc.
 150 2 0
Holland Forest
 139 1 0
Fox Meadow
 128 1 0
Cook's Trailer Court (aka Garrett Tp)
 120 1 1
Christmas Tree Farm Trailer Park
 100 3 0
Hearts Desire
 65 1 0
Mulberry South
 65 1 0
Wild Goose Crest Subdivision
 65 1 0
Non-community systems (164: schools, campgrounds, workplaces, restaurants)

These systems serve places people visit rather than homes.

SystemServesStatusRules violated, 3 yrUnresolved
Chopticon High School
 1,845 0 0
Leonardtown High School
 1,750 0 0
Leonardtown Middle School & Forrest Tech
 1,200 0 0
Webster Field Annex, ST Inigoes (navfac)
 1,200 1 0
Spring Ridge Middle School
 1,075 0 0
Margaret Brent Middle School
 1,050 0 0
Bradford's Neishyahood Market
 818 0 0
Seven Eleven # 21067 Charlotte Hall
 805 0 0
Point Lookout State Park North
 803 0 0
Piney Point Elementary School
 665 0 0
Lettie Marshall Dent Elementary
 650 0 0
Immaculate Conception Roman Cath Chur
 614 0 0
Saint Josephs Catholic Church
 602 0 0
Benjamin Banneker Elementary School
 600 0 0
Hollywood Elementary School
 600 0 0
Potomac Speedway
 510 0 0
Sacred Heart Church
 502 0 0
Saint Georges Catholic Church
 502 0 0
Saint Marys Fairgrounds
 502 0 0
Oakville Elementary School
 475 0 0
Patuxent Presbyterian Church
 464 0 0
Dynard Elementary School
 450 0 0
Hollywood Volunteer Fire Hall
 406 0 0
Seven Eleven # 20835 Mechanicsville
 403 0 0
Our Lady of the Wayside Church
 402 0 0
Saint Francis Xavier Church
 402 0 0
Little Flower School
 380 1 0
Mechanicsville Elementary
 350 0 0
Leonardtown S.h.a./ S.h.a. Maint.
 336 0 0
Mount Zion Umc at Laurel Grove
 335 0 0
Park Hall Liquors and Deli
 330 0 0
Mechanicsville Moose Lodge #495
 327 0 0
White Marsh Elementary School
 325 0 0
Avenue 7th District Volunteer Fire Hall
 310 0 0
Chaptico Market
 310 0 0
Wawa Mechanicsville #583
 308 0 0
Greenwell State Park
 304 0 0
Point Lookout State Park South
 304 0 0
Faith Bible Church
 303 0 0
Cecil Park Concession Stand
 301 0 0
Chaptico Park
 301 0 0
Dorsey Park Concession Stand
 301 0 0
Ridge Elementary School
 300 0 0
Camp Merryelande
 281 0 0
Mechanicsville Volunteer Fire Hall
 260 0 0
Foxy Fish
 250 0 0
Mother Catherine Academy
 250 0 0
Ridge Volunteer Fire Hall
 215 0 0
Birdies
 212 0 0
Budds Creek Motocross
 208 0 0
Seafood Corner Mkt and Big Dogs Paradise
 208 0 0
Fastop Leonardtown
 206 0 0
Our Ladys Church at Medleys Neck
 181 0 0
St. Michael's School
 180 0 0
Our Fathers House
 165 0 0
Capt. Leonards Seafood Market
 160 0 0
Bear Creek Bbq
 154 0 0
Brome Howard Inn
 154 0 0
Tools Bar
 154 0 0
Saint Clements Island-Pot. River Museum
 153 0 0
Saint Peter Claver
 151 1 0
Second District Vol. Fire Dept. & Rescue
 144 0 0
The Island Inn Bar and Grill
 137 0 0
Camp Maria
 135 0 0
Abells Diner/ Andersons Bar
 133 0 0
Saint Marys City Visitor Center
 133 0 0
Drift Inn
 132 0 0
Adf Catering and Charity Games North
 130 0 0
Holy Angels Church
 123 0 0
Saint Pauls Lutheran Church
 122 0 0
Victory Baptist Church
 121 0 0
Dennis Point Marina & Campground
 111 0 0
Sandgates Inn
 109 0 0
Korner Karryout
 107 0 0
Stoney's Restaurant
 106 0 0
Burchmart Hollywood
 104 0 0
Elms Beach Environmental Center
 104 0 0
Living Word Community Church
 103 0 0
Gospel Tabernacle of Prayer
 102 0 0
Saint Andrews Play School & Epis Church
 102 0 0
Saint Cecilias Church
 102 0 0
Bay Montessori School
 100 2 1
Benjamin Banneker Early Childhood Center
 100 0 0
Creative Beginnings Pre-School & Daycare
 100 0 0
Take-It-Easy Campground Retreat
 100 1 0
Zion United Methodist Church
 100 0 0
Big Boys Tacos
 91 0 0
Pier 450
 88 0 0
Christ Episcopal Church
 82 0 0
Saysf Bible Church
 82 0 0
Blackstone Marina
 80 1 0
Camp Riverview
 70 0 0
The Center for Life Enrichment
 70 1 0
Los Guayabos Mexican Grill
 68 0 0
Fiesta Cafe
 67 0 0
Hot Pot Chinese Restaurant, Inc.
 66 0 0
Cooks Liquor and Deli (hillville)
 65 0 0
Piney Point Market
 64 0 0
Hollywood Church of the Nazarene
 62 0 0
Gospel Light Baptist Church
 60 0 0
All 164 in the systems table
Inactive systems (286, no longer operating or reporting)

Kept for the record and excluded from the county totals above. Browse inactive systems.

About this data

Totals cover active systems. Systems serving more than one county are counted in each county. EPA counts the rules a system was in violation of, not the individual violations; one rule can carry several.

Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Maryland records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.