LABORATORY AND FIELD ANALYSES: In Section R317-2-10, a clause was added to provide flexibility of field methods that are different than Division of Water Quality standard procedures. SHEEP CREEK USE CHANGE: The Class 1C designated use (drinking water source) was applied to Sheep Creek, Cache County based on a request from a homeowners association and the Utah Division of Drinking Water. SILVER CREEK TDS CRITERION: The total dissolved solids (TDS) criterion was revised for upper Silver Creek in Summit County from 1,200 mg/L to 1,900 mg/L in Table 2.14.1. JORDAN RIVER AMMONIA CRITERIA: The aquatic life criteria for ammonia for segments of the Jordan River, Surplus Canal, and Mill Creek, Salt Lake County were changed based on updated information regarding the toxicity of ammonia and studies characterizing the aquatic life in these segments in Table 2.14.2. NUTRIENT CRITERIA: In Section R317-2-14 (Numeric Criteria), new Table 2.14.7 was added for nutrient criteria applicable to Antidegradation Category 1 and 2 waters statewide. These criteria are needed to ensure that Utah's headwaters continue to deliver high quality water to, for instance, drinking water. Nitrogen and phosphorus (nutrients) criteria were developed and applied to Category 1 and Category 2 waters in new Tables 2.14.7 and 2.14.8. UPDATES AND CORRECTIONS: In Section R317-2-14, Tables 2.14.1 and 2.14.6, several corrections were made to the statewide human health criteria. The aquatic life cadmium chronic criterion formula was corrected. The corrections to Tables 2.14.1, 2.14.2 and 2.14.6 were because the 2018 revisions (Utah State Bulletin, No. 2018-7, April 1, 2018, Filing No. 42691) were not implemented as intended.