If a shallow-water bay grass designated use segment meets its SAV restoration 
acreage, that designated use-segment is considered in attainment of the designated 
use and should be listed on part 2. 
If a shallow-water bay grass designated use segment does not meet its SAV restora¬ 
tion acreage and sufficient shallow-water monitoring data is available, the 
jurisdiction can then assess attainment of the designated use using water clarity acres 
or water clarity criteria as described below. If the water clarity acres/water clarity 
criteria are met/attained based on assessment of spatially intensive shallow-water 
monitoring data, then that designated use-segment is considered in attainment of the 
shallow-water bay grasses designated use and should be listed on part 2. 
If the water clarity acres/water clarity criteria are not met/attained based on assess¬ 
ment of shallow-water monitoring data, or if there is insufficient data to make a 
determination using water clarity acres, then that designated use-segment is consid¬ 
ered not in attainment of the shallow-water bay grasses designated use and should be 
listed on part 5. 
For those segments that contain the shallow-water bay grass designated use, attain¬ 
ment of this use should be assessed with the following procedure: 
If the segment's single best year SAV acreage (described below) drawn 
from the most recent three-year period of available data is equal to or greater 
then the state adopted SAV restoration acreage for that segment, then that 
segment is considered to be in attainment of its shallow-water bay grass 
designated use. If the segment’s single best year SAV acreage is less than 
the state adopted SAV restoration acreage for that segment, the state should 
then proceed to assess water clarity acres if sufficient shallow-water data is 
available, otherwise, the segment is not in attainment. 
If the segment’s water clarity acres (defined below) calculated from the 
most recent three-year period of available shallow-water monitoring water 
clarity data is equal to or greater than state adopted water clarity restoration 
acreage for that segment, then that segment is considered to be in attainment 
of its shallow-water bay grass designated use. If the segment’s water clarity 
acres are less than the state adopted water clarity restoration acreage for that 
segment, then that segment is considered not to be in attainment of its 
shallow-water designated use unless SAV acreage data indicate attainment. 
A jurisdiction may also choose to apply the CFD-based assessment of water 
clarity criteria, described in more detail below, in place of water clarity acres, to 
assess attainment of the segment's shallow-water bay grass designated use. 
Given that SAV is the ultimate biological measure of attainment of the designated 
use, the EPA recommends a specific sequence of criteria assessment: assessment of 
SAV acres meeting the segment-specific restoration acres first, followed by assess¬ 
ment of water clarity acres or water clarity criteria attainment. In the absence of 
sufficient shallow-water monitoring data to determine the available water clarity 
acres or assess water clarity criteria attainment using the CFD-based procedure, the 
chapter v 
Refinements to the Shallow-Water Dcsignated-Usc Assessment Procedure 
