Water Quality Data Standards

First Regular Session Seventy-fourth General Assembly STATE OF COLORADO INTRODUCED HOUSE BILL 23-1221 LLS NO. 23-0396.02 Sarah Lozano x3858 HOUSE SPONSORSHIP Soper and Mauro, Marshall SENATE SPONSORSHIP Simpson, House Committees Senate Committees Energy & Environment A BILL FOR AN ACT CONCERNING DATA STANDARDS FOR THE DETERMINATION OF A TOTAL MAXIMUM DAILY LOAD FOR STATE WATERS.

Bill Summary (Note: This summary applies to this bill as introduced and does not reflect any amendments that may be subsequently adopted. If this bill passes third reading in the house of introduction, a bill summary that applies to the reengrossed version of this bill will be available at http://leg.colorado.gov.) The bill requires the division of administration in the department of public health and environment, on and after January 1, 2024, to use quality-assured data to determine the maximum amount of a pollutant that can be discharged daily into state waters without exceeding applicable water quality standards.

Shading denotes HOUSE amendment. Double underlining denotes SENATE amendment.

Capital letters or bold & italic numbers indicate new material to be added to existing law. Dashes through the words or numbers indicate deletions from existing law.

Be it enacted by the General Assembly of the State of Colorado: SECTION 1. In Colorado Revised Statutes, 25-8-103, add (17.3) and (19.5) as follows: 25-8-103. Definitions. As used in this article 8, unless the context otherwise requires:

"QUALITY-ASSURED DATA" MEANS SCIENTIFICALLY ACCURATE DATA RELATED TO WATER QUALITY THAT HAS BEEN COLLECTED IN THE LAST FIVE YEARS OR IN THE MOST RECENT PERIOD OF TIME IN WHICH COMPARABLE DATA WAS ANALYZED, WHICHEVER IS LATER, AND THAT COMPLIES WITH:

(a) THE COMMISSION'S RULES PURSUANT TO THIS ARTICLE 8, INCLUDING THE COMMISSION'S RULES REGARDING HOW WATER QUALITY DATA IS COLLECTED, ANALYZED, AND ASSESSED; AND

(b) FEDERAL AND STATE GUIDANCE ON WATER QUALITY DATA COLLECTION BEST PRACTICES, RELIABLE ANALYTICAL METHODS, AND DATA QUALITY ASSURANCES.

(19.5) "TOTAL MAXIMUM DAILY LOAD" MEANS THE CALCULATION OF THE MAXIMUM AMOUNT OF A POLLUTANT THAT CAN BE DISCHARGED DAILY INTO STATE WATERS WITHOUT EXCEEDING AN APPLICABLE WATER QUALITY STANDARD.

SECTION 2. In Colorado Revised Statutes, 25-8-501, add (7) as follows: 25-8-501.

Permits required for discharge of pollutants - administration - total maximum daily load. (7) ON AND AFTER JANUARY 1, 2024, IN DETERMINING A TOTAL MAXIMUM DAILY LOAD FOR STATE WATERS, THE DIVISION SHALL USE QUALITY-ASSURED DATA TO ESTABLISH THAT THE TOTAL MAXIMUM DAILY LOAD IS CALCULATED WITH COMPREHENSIVE GEOGRAPHIC AND HYDROGEOLOGIC ACCURACY.

SECTION 3. Act subject to petition - effective date. This act takes effect January 1, 2024; except that, if a referendum petition is filed pursuant to section 1 (3) of article V of the state constitution against this act or an item, section, or part of this act within the ninety-day period after final adjournment of the general assembly, then the act, item, section, or part will not take effect unless approved by the people at the general election to be held in November 2024 and, in such case, will take effect on the date of the official declaration of the vote thereon by the governor.