| CAMBRIDGE FARMS | | 953 | 0.1360 mg/L |
| JUBILEE MHP | | 30 | 0.0548 mg/L |
| ECHO VALLEY MHP | | 60 | 0.0441 mg/L |
| GLEN MEADOWS RETIREMENT COMMUNITY | | 468 | 0.0420 mg/L |
| ENCHANTED ACRES MHC LLC | MILLSBORO | 225 | 0.0343 mg/L |
| PINEY CREEK CORPORATION | | 31 | 0.0290 mg/L |
| WOODBINE VILLAGE MOBILE HOME PARK | | 150 | 0.0290 mg/L |
| GOLDEN KAY APARTMENTS | | 148 | 0.0267 mg/L |
| PLEASANT HILL MOBILE HOME PARK | | 64 | 0.0250 mg/L |
| BAY COUNTRY ESTATES MOBILE HOME PARK | | 276 | 0.0247 mg/L |
| TOWN OF EMMITSBURG | | 2,921 | 0.0240 mg/L |
| TODD VILLAGE MOBILE HOME PARK | | 180 | 0.0219 mg/L |
| LONDONDERRY COURT MHP | | 160 | 0.0208 mg/L |
| MAPLE HILL MOBILE ESTATES | | 180 | 0.0206 mg/L |
| BENNETT MOBILE HOME PARK | | 60 | 0.0202 mg/L |
| TOWN OF BETTERTON | | 481 | 0.0200 mg/L |
| BENJAMINS VILLAGE/HOMESTEAD M.H.P. | | 400 | 0.0188 mg/L |
| NAYLOR MILL VILLAGE MOBILE HOME PARK | | 180 | 0.0187 mg/L |
| TOWN OF PITTSVILLE | | 1,500 | 0.0184 mg/L |
| TOWN OF THURMONT | | 6,200 | 0.0184 mg/L |
| WEST NOTTINGHAM ACADEMY | | 250 | 0.0183 mg/L |
| ROCKBROOK VILLAGE MOBILE HOME PARK | | 150 | 0.0182 mg/L |
| CITY OF CUMBERLAND | | 27,039 | 0.0178 mg/L |
| SAINT JAMES SCHOOL | | 200 | 0.0175 mg/L |
| CEDARHURST MOBILE HOME PARK | | 220 | 0.0174 mg/L |
| TEBBSTON ON MAGOTHY | | 52 | 0.0164 mg/L |
| REGENCY PARK ASSISTED LIVING RESIDENCE | | 85 | 0.0160 mg/L |
| TOWN OF SMITHSBURG DISTRIBUTION SYSTEM | | 2,500 | 0.0160 mg/L |
| SULLIVANS MOBILE HOME PARK COMMUNITY | | 70 | 0.0156 mg/L |
| TOWN OF DEER PARK | | 272 | 0.0156 mg/L |
| TRIPLE J MHP | | 200 | 0.0154 mg/L |
| ELK RIDGE LAKE | | 120 | 0.0153 mg/L |
| DELMAR UTILITY COMM (TN OF DELMAR) | DELMAR | 2,027 | 0.0151 mg/L |
| CITY OF FROSTBURG | | 11,000 | 0.0150 mg/L |
| MOUNT SAINT MARYS UNIVERSITY | | 1,900 | 0.0150 mg/L |
| BOH-NAK MOBILE HOME PARK | | 85 | 0.0150 mg/L |
| PLEASANT VIEW NURSING HOME | | 104 | 0.0147 mg/L |
| PINE TREE MOBILE HOME PARK | | 91 | 0.0147 mg/L |
| IRISH CREEK MHP | | 90 | 0.0144 mg/L |
| PLEASANT VALLEY | | 150 | 0.0144 mg/L |
| FOX RUN CONDOMINIUMS, INC. | | 85 | 0.0140 mg/L |
| ALTAMAHA MOBILE HOME VILLAGE | BRUNSWICK | 143 | 0.0138 mg/L |
| HOLLY OAK MOBILE HOME PARK | DELMAR | 210 | 0.0137 mg/L |
| TOWN OF LUKE | | 68 | 0.0136 mg/L |
| GATEWAY VILLAGE MOBILE HOME PARK | | 60 | 0.0136 mg/L |
| REX HILL ESTATES, LLC | | 246 | 0.0135 mg/L |
| CLAIBORNE | | 60 | 0.0135 mg/L |
| TOWN OF OCEAN CITY | | 30,000 | 0.0133 mg/L |
| FREEDOM DISTRICT | | 24,867 | 0.0133 mg/L |
| MARTINGHAM UTILITIES COOPERATIVE | | 675 | 0.0131 mg/L |
| KNOLLS OF WINDSOR | | 1,553 | 0.0131 mg/L |
| TOWN OF WOODSBORO | | 846 | 0.0130 mg/L |
| TOWN OF MIDDLETOWN | | 4,288 | 0.0129 mg/L |
| STEEPLECHASE WATERWORKS | | 395 | 0.0126 mg/L |
| BOONES MOBILE ESTATES | | 1,315 | 0.0126 mg/L |
| HIGHFIELD | | 1,141 | 0.0126 mg/L |
| MARYLAND AMERICAN WATER COMPANY | | 13,200 | 0.0126 mg/L |
| TOWN OF NORTH EAST | | 8,600 | 0.0126 mg/L |
| CITY OF BALTIMORE | | 1,600,000 | 0.0125 mg/L |
| HOWARD COUNTY D.P.W. DISTRIBUTION | | 286,158 | 0.0124 mg/L |
| DOVE ESTATES | SEAFORD | 111 | 0.0124 mg/L |
| GARRETT CHILDREN'S CENTER | | 45 | 0.0124 mg/L |
| BRIDDLETOWN DISTRIBUTION SYSTEM | | 150 | 0.0123 mg/L |
| TOWN OF FRIENDSVILLE | | 622 | 0.0122 mg/L |
| CRYSTAL BEACH MANOR/T&C UTILITY | | 500 | 0.0121 mg/L |
| WINDWARD KNOLL MHP | THONOTOSASSA | 208 | 0.0121 mg/L |
| TOWN & COUNTRY MOBILE HOME PARK | | 950 | 0.0121 mg/L |
| HARBOUR LIGHT ESTATES COMMUNITY | | 95 | 0.0120 mg/L |
| WOODLAWN MOBILE HOME PARK - OLD | | 50 | 0.0120 mg/L |
| CEDAR RIDGE CHILDREN'S HOME & SCHOOL | | 45 | 0.0120 mg/L |
| TOWN OF GRANTSVILLE | | 885 | 0.0119 mg/L |
| TOWN OF CECILTON | | 477 | 0.0117 mg/L |
| CITY OF WESTMINSTER | | 35,256 | 0.0116 mg/L |
| TOWN OF SUDLERSVILLE | | 497 | 0.0116 mg/L |
| FOUNTAIN GREEN MOBILE HOME PARK | | 55 | 0.0114 mg/L |
| GRAMERCY LLC (AKA KOINONIA PARTNERSHIP ) | | 40 | 0.0114 mg/L |
| RIDDLE FARM | | 500 | 0.0112 mg/L |
| FAHRNEY-KEEDY SENIOR LIVING COMMUNITY | | 250 | 0.0111 mg/L |
| CITY OF FREDERICK | | 54,000 | 0.0110 mg/L |
| HAWTHORNE WATER SUPPLY, INC | | 60 | 0.0110 mg/L |
| WASHINGTON SUBURBAN SANITARY COMMISSION | | 1,900,000 | 0.0110 mg/L |
| TOWN OF HENDERSON | | 156 | 0.0110 mg/L |
| GILBERTS MOBILE HOME PARK | | 75 | 0.0110 mg/L |
| TWIN ARCH MOBILE HOME PARK | | 50 | 0.0110 mg/L |
| LIBERTY MOBILE HOME PARK | | 40 | 0.0110 mg/L |
| MAYO CENTER AND APARTMENTS | | 60 | 0.0109 mg/L |
| TOWN OF RISING SUN | | 2,200 | 0.0108 mg/L |
| POLINGS MOBILE HOME PARK | | 80 | 0.0108 mg/L |
| HART HERITAGE | | 37 | 0.0107 mg/L |
| TOWN OF MYERSVILLE | | 1,516 | 0.0107 mg/L |
| CHAPEL HILL - ABERDEEN PROVING GROUNDS | | 15,000 | 0.0106 mg/L |
| TOWN OF PRESTON | | 750 | 0.0106 mg/L |
| FORT DETRICK | | 7,900 | 0.0106 mg/L |
| OAK RIDGE MOBILE HOME PARK | | 150 | 0.0101 mg/L |
| TOWN OF OXFORD | | 726 | 0.0101 mg/L |
| SHORES OF CALVERT | | 361 | 0.0101 mg/L |
| THUNDERBIRD APARTMENTS | | 40 | 0.0101 mg/L |
| VILLAS AT CATTAIL CREEK | | 170 | 0.0101 mg/L |
| TOWN OF WALKERSVILLE | | 8,440 | 0.0100 mg/L |
| MIDLAND-LONACONING | | 5,000 | 0.0100 mg/L |