PDFWAC 173-481-100
Forage standards.
(1) All sampling to determine compliance with these standards shall be conducted in locations and during time periods consistent with protecting livestock.
(2) The fluoride content of forage calculated by dry weight shall not exceed:
(a) Forty parts per million fluoride ion (40 ppm F-) average for the growing season.
(b) Sixty parts per million fluoride ion (60 ppm F-) each month for more than two consecutive months during the growing season.
(c) Eighty parts per million fluoride ion (80 ppm F-) more than once in any two consecutive months during the growing season.