1. THE WATER QUALITY OF LOCAL WATER SOURCES MUST MEET REQUIREMENTS 1. Sanitary norms and rules 2.13684-21 2. GOST 2761-84 3. Sanitary rules and norms 2.1.3685

The correct answer is:<br /><br />1. Sanitary norms and rules $2.13684-21$<br /><br />Explanation:<br />The water quality of local water sources must meet sanitary norms and rules, specifically the ones outlined in the document $2.13684-21 standards and requirements for water quality to ensure it is safe and suitable for consumption and use.