Revised Assessments for Waters Potentially Impaired for Criteria Expressed Relative to Natural Background for the Group 1 (Cycle 3) Basins

Please Note: Revisions to the Group 1 Lists of Impaired Waters

The criteria for assessing several parameters are dependent on the comparison of values against background or natural background. It is challenging to determine what represents “background” for some of the systems in Florida requiring very site-specific data collections. The parameters that fall into this category are pH, alkalinity, turbidity, and specific conductance. For the determination of impairment, the FDEP performs a preliminary assessment for these parameters according to the following:

Assessment Criteria Implemented for Select Parameters through the IWR database

Parameter	Waterbody Class	Criteria	Assessment
pH	Class I & IIIF	ph measurement < 6.0 > 8.5 S.U.	Potentially Impaired
pH	Class II and IIM	ph measurement < 6.5 > 8.5 S.U.	Potentially Impaired
Alkalinity	Class I and IIIF	Alkalinity results < 20 mg/L	Potentially Impaired
Specific Conductance	Class I and IIIF	SpCond measurement > 1275 umhos/cm	Potentially Impaired
Turbidity	Class I, II, IIIF & IIIM	Turbidity measurements > 29 N.T.U	Potentially Impaired

IIIF - Predominantly fresh waters
IIIM - Predominantly marine waters

The WBIDs in the following table are considered to be impaired based on the preliminary assessment of these parameters.  The Department requests information from stakeholders that may assist in determining the appropriate assessment of these parameters for these waterbodies.  Specifically, information on the presence of pollutant sources and background conditions that could be used for comparison.  Since the above criteria do not fully implement the criteria as stated in 62-302 F.A.C., these WBIDs are placed into category 3c and included on the planning list if the impairment cannot be verified.  This action ensures that the waterbodies are included for strategic monitoring during the next cycle and background conditions can be established.

Note: In an attempt to make commenting on the lists easier, we have designed these lists to provide information regarding the DRAFT assessments and the REVISED assessments. The first two columns in each list indicate whether or not the assessment was on the DRAFT list and/or the REVISED list and the comments provide information on why the assessment may have changed. To determine what is NEW from the draft lists, one can look at those rows where the first column is blank and the second column contains an ‘R’. These represent what is being proposed as the final assessments for the Group 1 basins through the third cycle.