MIL-HDBK-1005/9A
serve both is adequate. Refer to EPA 430-99-74-001, Design
Criteria for Mechanical, Electrical, and Fluid System Component
Reliability (MCD-29).
4.7.3
Sampling. Institute sampling programs only as needed
to obtain data for the design and operation of wastewater
treatment facilities, or to determine compliance with standards
and the effect of waste streams (both raw and treated) on
receiving waters. Refer to American Society for Testing and
Materials (ASTM) D 3370, Sampling Water, for general discussion
of sampling water and wastewater.
4.7.3.1
Sampling Techniques
a) Collection Point. Collect all samples in conduits
or channels at point where flow is highly turbulent. Collect
sample from process tank only if tank contents are well mixed.
Consider width, length, and depth when selecting sampling point
from process tank.
b) Type of Sample. Use samples composited on basis
of time and flow, but take single grab samples when:
(1) Wastewater stream is intermittent or
concentration is highly variable.
(2) Obtaining information for which time between
collection and analysis of sample must be minimized (for
example, sampling for dissolved oxygen, temperature, pH,
chlorine demand, and residual chlorine; these cannot be
composited).
(3) Ascertaining characteristics at extreme
conditions.
(4) Samples for oil and grease may be manually
composited.
Automatic sampling is not normally accurate.
c) Method of Sampling. Use widemouthed containers to
take grab samples. At small plants (up to 1 Mgd [3.8 x 106
L/d]), take composite samples manually by combining a series of
regularly collected grab samples, such that the contribution
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