Middle St. Johns - Florida Department of Environmental Protection

252 Water Quality Assessment Report: Middle St. Johns
EVALUATION OF TOXICITY DATA
Although the Impaired Surface Waters Rule describes the use of toxicity data for the
assessment of aquatic life-based attainment, no ambient toxicity data are available for
assessment and this metric was not used.
Primary Contact and Recreation Attainment
For Class I, II, or III waters, a waterbody was potentially impaired if the following
criteria were met:
• The waterbody segment did not meet the applicable water quality criteria for
bacteriological quality,
• The waterbody segment included a bathing area that was closed by a local health
department or county government for more than one week or more than once during
a calendar year based on bacteriological data,
• The waterbody segment included a bathing area for which a local health department
or county government issued closures, advisories, or warnings totaling twenty-one
days or more during a calendar year based on bacteriological data,
• The waterbody segment included a bathing area that was closed or had advisories or
warnings for more than twelve weeks during a calendar year based on previous
bacteriological data or on derived relationships between bacteria levels and rainfall
or flow.
Fish and Shellfish Consumption Attainment
For Class I, II, or III waters, a waterbody was potentially impaired if it did not meet
the applicable Class II water quality criteria for bacteriological quality, or if a fish
consumption advisory had been issued. Fish consumption advisories were based on the
Florida Department of Health’s “limited consumption” or “no consumption” advisories
for surface waters because of high levels of mercury in fish tissue. In addition, for Class
II waters, waterbody segments that had been approved for shellfish harvesting but were
downgraded to a more restrictive classification were listed as potentially impaired.
Drinking Water Attainment and Protection of Human Health
For Class I waters, a waterbody was potentially impaired if it did not meet the
applicable Class I water quality criteria.