Table 6- 7. Requirements for Special Design Elements
Section of 40 CFR 264 Describing Requirements
Dikes are designed, constructed, and maintained
with sufficient structural integrity to prevent
massive failure of the dikes. In ensuring structural
integrity, it must not be presumed that the liner
system will function without leakage during the
active life of the
Weekly inspection for severe erosion or other signs
The unit must be designed, constructed,
maintained, and operated to prevent overtopping
resulting from normal or abnormal operations
overfilling; wind and wave action; rainfall; run- on;
malfunctions of level controllers, alarms
and other equipment; and human error.
Weekly inspections to detect evidence of
of overtopping control
If the unit contains any particulate matter
which may be subject to wind dispersal, the owner
or operator must cover or otherwise manage the
unit to control
Inspected weekly and after storms for proper
functioning of wind dispersal l
* No standards or requirements established.
Adapted from 40 CPFR 264
posed or existing dike system is of primary importance;
*For flow-through units: adequately sized
slope failure due to saturation, earthquake or poor
construction could result in extensive environmental,
structures which can maintain a constant
property and human damage.
liquid level and freeboard.
(2) Stability assessments should utilize in situ
-pipes with valved intakes and outlets for
properties of the dikes and foundations and pertinent
Assessment methods and
-pumping systems for control of inflows
evaluative criteria are presented in NAVFAC DM 7.1 and
EPA SW-873. Evaluations and monitoring must be
For units without outlets: provisions to
repetitive to ensure structural integrity and containment
assess the freeboard level and regulate
inflow to prevent overtopping.
Prevention of overtopping.
(2) A 2-foot freeboard is documented as
impoundments must be designed, constructed,
providing sufficient protection against overtopping due to
maintained and operated to prevent overtopping.
inflow fluctuations or wave action; however, when
Designing impoundments with significant freeboard,
manual operation is involved, greater freeboards may be
establishing operating practices to monitor and regulate
necessary to ensure protection.
liquid levels, using automatic liquid level controllers,
(3) Water balance studies must be performed for
and/or using alarms can prevent overtopping.
(1) Specific guidance requirements to preventing
* For stormwater: design and operating
levels. The EPA believes stormwater should be diverted
provisions which can withstand, at a
from surface impoundments.
The guidelines to
minimum, the flow generated by a 24-hour,
accomplish this are that structures be designed to di-