D.C. Code § 8-104.02

For the purposes of this subchapter, the term:
(1) “Department” means the District Department of the Environment.
(2) “Enhanced efficiency fertilizer” means a fertilizer product with characteristics that allow increased plant uptake and reduces the potential of nutrient loss to the environment, such as gaseous loss, leaching, or runoff, when compared to an appropriate reference fertilizer product.
(3) “Fertilizer” means a material that contains one or more nutrients intended to promote plant growth.
(4) “Low phosphorus fertilizer” means a fertilizer containing no more than 5% of available phosphate (P2O5), and that has an application rate not to exceed 0.25 pound of available phosphate (P2O5)/1,000 square feet/application and 0.5 pound of available phosphate (P2O5)/1,000 square feet/year.
(5) “Organic fertilizer” means a material that:
(A) Is derived from either plant or animal products containing one or more elements that are essential for plant growth, other than carbon, hydrogen, and oxygen;
(B) May be subjected to biological degradation processes under normal conditions of aging, rainfall, sun-curing, air drying, composting, rotting, enzymatic, or anaerobic/aerobic bacterial action; and
(C) May not be mixed with synthetic materials or changed in a physical or chemical manner from their initial state, except by manipulation such as drying, cooking, chopping, grinding, shredding, hydrolysis, or pelleting.
(6) “Soil test” means a scientific measurement that determines the nutrient levels of soil.
(7) “Turf” means nonagricultural managed grasses, such as the grasses found at parks, recreation areas, golf courses, commercial locations, cemeteries, athletic fields, schools, universities, government grounds, residential lawns, and other similar nonagricultural managed grasses. The term “turf” does not include non-grass groundcovers, shrubs, trees, vegetable and flower gardens, and indoor applications such as greenhouses.
ural managed grasses, such as the grasses found at parks, recreation areas, golf courses, commercial locations, cemeteries, athletic fields, schools, universities, government grounds, residential lawns, and other similar nonagricultural managed grasses. The term “turf” does not include non-grass groundcovers, shrubs, trees, vegetable and flower gardens, and indoor applications such as greenhouses.
(8) “Waterbody” means a wetland, watercourse, river, stream, creek, storm water retention or detention basin, or other similar water resource.