U.S. Code of Federal Regulations

Regulations most recently checked for updates: May 25, 2024

§ 439.1 - General definitions.

As used in this part:

(a) The general definitions, abbreviations and methods of analysis in 40 CFR part 401 shall apply.

(b) Bench-scale operation means the laboratory testing of materials, methods, or processes on a small scale, such as on a laboratory worktable.

(c) Cyanide (T) means the parameter total cyanide.

(d) In-plant monitoring point means a location within a plant, where an individual process effluent can be exclusively monitored before it is diluted or mixed with other process wastewaters en route to the end-of-pipe.

(e) Maximum daily means the highest allowable discharge of wastewater pollutants during a calendar day or any 24 hour period that reasonably represents a calendar day for purposes of sampling.

(f) Maximum monthly average means the highest allowable average of daily discharges of wastewater pollutants over a calendar month, and is calculated as the sum of all daily values measured during a calendar month divided by the number of daily values measured during that month.

(g) mg/L means milligrams per liter or parts per million (ppm)

(h) Minimum level means the level at which an analytical system gives recognizable signals and an acceptable calibration point.

(i) Nitrification capability means the capability of a POTW treatment system to oxidize ammonia or ammonium salts initially to nitrites (via Nitrosomonas bacteria) and subsequently to nitrates (via Nitrobacter bacteria). Criteria for determining the nitrification capability of a POTW treatment system are: bioassays confirming the presence of nitrifying bacteria; and analyses of the nitrogen balance demonstrating a reduction in the concentration of ammonia or ammonium salts and an increase in the concentrations of nitrites and nitrates.

(j) Non-detect (ND) means a concentration value below the minimum level that can be reliably measured by the analytical method.

(k) Pilot-scale operation means processing equipment being operated at an intermediate stage between laboratory-scale and full-scale operation for the purpose of developing a new product or manufacturing process.

(l) POTW means publicly owned treatment works (40 CFR 403.3).

(m) Process wastewater, as defined at 40 CFR 122.2 and for the purposes of this part, does not include the following:

(1) Trimethyl silanol, any active anti-microbial materials, process wastewater from imperfect fermentation batches, and process area spills. Discharges containing such materials are not subject to the limitations and standards of this part.

(2) Non-contact cooling water, utility wastewaters, general site surface runoff, groundwater (e.g., contaminated groundwaters from on-site or off-site groundwater remediation projects), and other non-process water generated on site. Discharges of such waters and wastewaters are not subject to the limitations and standards of this part.

(n) Non-conventional pollutants means parameters that are neither conventional pollutants (40 CFR 401.16), nor “toxic” pollutants (40 CFR 401.15).

(o) Surrogate pollutant means a regulated parameter that, for the purpose of compliance monitoring, is allowed to serve as a surrogate for a group of specific regulated parameters. Plants would be allowed to monitor for a surrogate pollutant(s), when the other parameters for which it stands are receiving the same degree of treatment as the surrogate pollutant(s) and all of the parameters discharged are in the same treatability class(es) as their respective surrogate pollutant(s). Treatability classes have been identified in appendix A of this part for both steam stripping and biological treatment technologies, which are the respective technology bases for PSES/PSNS and BAT/NSPS limitations controlling the discharge of regulated organic parameters.

(p) Xylenes means a combination of the three isomers: o-xylene, m-xylene, and p-xylene.

[63 FR 50425, Sept. 21, 1998; 64 FR 48104, Sept. 2, 1999, as amended at 68 FR 12270, Mar. 13, 2003]