Culligan serves Ashburnham, Athol, Auburn, Baldwinville, Barre, Berlin, Blackstone, Bolton, Boylston, Brimfield, Brookfield, Charlton, Charlton City, Charlton Depot, Cherry Valley, Clinton, Devens, Douglas, Dudley, East Brookfield, East Princeton, East Templeton, Fiskdale, Fitchburg, Gardner, Gilbertville, Grafton, Hardwick, Harvard, Holden, Holland, Hopedale, Hopkinton, Hubbardston, Jefferson, Lancaster, Leicester, Leominster, Linwood, Lunenburg, Manchaug, Mendon, Milford, Millbury, Millville, New Braintree, North Brookfield, North Grafton, North Oxford, North Uxbridge, Northborough, Northbridge, Oakham, Oxford, Paxton, Petersham, Princeton, Rochdale, Royalston, Rutland, Shrewsbury, South Barre, South Grafton, South Lancaster, Southborough, Southbridge, Spencer, Sterling, Still River, Sturbridge, Sutton, Templeton, Upton, Uxbridge, Warren, Webster, West Boylston, West Brookfield, West Millbury, West Warren, Westborough, Westminster, Wheelwright, Whitinsville, Winchendon, Winchendon Springs and Worcester.