…ms per square meter Biological Tissue None None None None None None Not checked 32228 Chlorophyll a, peri,spec,unc mg/m2 BIO Chlorophyll a, periphyton, spectrophotometric method, uncorrected, milligrams per square meter Biological Tissue None None None None None None Not checked …

…). [ 50 FR 1449 , Jan. 11, 1985, as amended at 70 FR 1630 , Jan. 7, 2005; 73 FR 32228 , June 5, 2008; 74 FR 6821 , Feb. 10, 2009; 81 FR 82020 , June 1, 2018] Editorial Note Editorial Note: For Federal Register citations affecting Form 12b-25, see the List of CFR Sections Affected…