40 CFR 417.151 - Specialized definitions.
For the purpose of this subpart:
(b) The term anhydrous product shall mean the theoretical product that would result if all water were removed from the actual product.
(c) The term surfactant shall mean those methylene blue active substances amenable to measurement by the method described in “Methods for Chemical Analysis of Water and Wastes,” 1971, Environmental Protection Agency, Analytical Quality Control Laboratory, page 131.
(d) The term normal operation of a spray tower shall mean operation utilizing formulations that present limitted air quality problems from stack gases and associated need for extensive wet scrubbing, and without more than 6 turnarounds in a 30 consecutive day period, thus permitting essentially complete recycle of waste water.
(e) The term air quality restricted operation of a spray tower shall mean an operation utilizing formulations (e.g., those with high non-ionic content) which require a very high rate of wet scrubbing to maintain desirable quality of stack gases, and thus generate much greater quantities of waste water than can be recycled to process.
(f) The term fast turnaround operation of a spray drying tower shall mean operation involving more than 6 changes of formulation in a 30 consecutive day period that are of such degree and type (e.g., high phosphate to no phosphate) as to require cleaning of the tower to maintain minimal product quality.
(g) The term BOD7 shall mean the biochemical oxygen demand as determined by incubation at 20 degrees C for a period of 7 days using an acclimated seed. Agitation employing a magnetic stirrer set at 200 to 500 rpm may be used.