Md. Code, Env't § 9-401

(a) In this subtitle the following words have the meanings indicated. (b) “Administrator” means the Administrator of the United States Environmental Protection Agency. (c) “Community water system” means a public water system that: (1) Serves at least 15 service connections used by year–round residents of the area served by the system; or (2) Regularly serves at least 25 year–round residents. (d) “Contaminant” means any chemical, biological, or radioactive substance that is harmful to health if in the water. (e) “Federal Act” means the federal Safe Drinking Water Act. (f) “Federal agency” means any department, agency, or instrumentality of the United States. (g) “National primary drinking water regulations” means the primary drinking water rules or regulations that the Administrator adopts under the federal Act. (h) “Noncommunity water system” means a public water system that is not a community water system. (i) “Nontransient noncommunity water system” means a public water system that is not a community system and that regularly serves at least 25 of the same individuals over 6 months per year. (j) “Person” includes: (1) The Washington Suburban Sanitary Commission; (2) Any State, county, municipal corporation, or federal agency; (3) Any special taxing area or district that operates a public water system; and (4) Any officer, agent, or employee of any of these. (k) “Primary drinking water regulation” means a rule or regulation that: (1) Applies to public water systems; (2) Specifies contaminants that, in the judgment of the Secretary, would have an adverse effect on the health of human beings; (3) Specifies for each contaminant either: (i) A maximum contaminant level if, in the judgment of the Secretary, it is economically and technologically feasible to determine the level of the contaminant in water in public water systems; or (ii) If, in the judgment of the Secretary, it is not economically or technologically feasible to determine the level of the contaminant, each treatment technique known to the Secretary that leads to a reduction in the level of the contaminant sufficient to satisfy the requirements of this subtitle; and (4) Contains standards and procedures: (i) To ensure a supply of drinking water that dependably complies with the maximum contaminant levels, including quality control and testing procedures for compliance with those levels; (ii) To ensure proper operation and maintenance of the system; and (iii) To establish requirements as to: 1. The minimum quality of water that may be taken into the system; and 2. Siting for new facilities for public water systems. (l) (1) “Public water system” means a system that: (i) Provides to the public water for human consumption through pipes or other constructed conveyances; and (ii) 1. Has at least 15 service connections; or 2. Regularly serves at least 25 individuals. (2) “Public water system” includes: (i) Any collection, treatment, storage, or distribution facility that is under the control of the operator of the system and is used primarily in connection with the system; and (ii) Any collection or pretreatment storage facility that is not under the control of the operator of the system and is used primarily in connection with the system. (m) “Supplier of water” means any person who owns or operates a public water system. (n) “Tamper” means to: (1) Introduce a contaminant into a public water system with the intention of harming a person; or (2) Otherwise interfere with the operation of a public water system with the intention of harming a person. (o) “Transient noncommunity water system” means a noncommunity water system that does not regularly serve at least 25 of the same individuals over 6 months per year.