D.C. Mun. Regs. tit. 22-B, § 501
501.1 When absent of any additional additives, the following pharmaceutical products may be disposed of by flushing the product down the drain or by another method that uses the sewer system:
(a) Sterile Water;
(b) Dextrose solutions such as five percent (5%) dextrose in water (D5W);
(c) Saline solutions such as nine tenths of a percent of sodium chloride (0.9% NaCl);
(d) Lactated Ringers;
(e) Potassium salts such as potassium chloride (KCl);
(f) Calcium salts such as calcium chloride (CaCl) and Calcium Gluconate; and
(g) Magnesium salts such as magnesium sulfate (MgSO4).
SOURCE: Final Rulemaking published at 60 DCR 9354 (June 21, 2013).