2018 Maryland Code
Environment
Title 9 - Water, Ice, and Sanitary Facilities
Subtitle 11 - Miscellaneous Sanitary Provisions
§ 9-1112. Residential use of graywater
(a) "Graywater" defined. -- In this section:
(1) " Graywater" means used, untreated water generated by the use of and collected from:
(i) A shower;
(ii) A bathtub; or
(iii) A lavatory sink; and
(2) " Graywater" does not include water from:
(i) A toilet;
(ii) A kitchen sink; or
(iii) A dishwashing machine.
(b) In general. --
(1) Subject to paragraph (2) of this subsection, and following the adoption of regulations as required by subsection (c) of this section, a person may use graywater for residential purposes including:
(i) Household gardening;
(ii) Composting;
(iii) Lawn watering;
(iv) Landscape irrigation; or
(v) Flushing of a conventional toilet or urinal.
(2) A person may use graywater if the use is permitted under regulations required by subsection (c) of this section, and:
(i) The graywater originates from a residence on the site on which the graywater is to be applied;
(ii) The graywater is contained in a storage tank that is located on the site on which the graywater is to be applied;
(iii) Human contact with graywater and soil irrigated by graywater is avoided;
(iv) Surface application of graywater is not used for irrigation of food plants that have an edible portion that comes in direct contact with graywater;
(v) The graywater does not contain hazardous chemicals derived from any activity, including:
1. Cleaning motor vehicle parts;
2. Washing greasy or oily rags; or
3. Disposing of waste solutions from home photo lab activities or similar hobbyist or home occupational activities;
(vi) The application of graywater is managed to minimize standing water on the surface of the ground;
(vii) The graywater system is constructed to provide for overflow into a sewerage system or an on-site sewage disposal system;
(viii) For a graywater storage tank located outdoors, the graywater storage tank is covered to restrict access and to eliminate habitat for mosquitoes and other vectors;
(ix) The graywater system is located outside the 100-year floodplain;
(x) The graywater system is operated to maintain a minimum vertical separation of at least 5 feet from the point of graywater application to the top of the seasonally high groundwater table;
(xi) Any pressure piping used in a graywater system that may be susceptible to cross connection with a potable water system clearly indicates that the piping does not carry potable water;
(xii) Graywater applied by surface irrigation does not contain water used to wash diapers or similarly soiled or infectious garments;
(xiii) Surface irrigation by graywater is conducted only by flood irrigation or drip irrigation if there is adequate irrigation area;
(xiv) The graywater is not sprayed;
(xv) The graywater does not run off or pond on-site;
(xvi) The graywater does not create nuisance conditions; and
(xvii) The graywater use is in accordance with any applicable State and local laws or regulations, including State and local plumbing codes.
(c) Regulations. -- The Department shall adopt regulations to implement the provisions of this section.