COALEX State Inquiry Report - 340
April, 1998

Tony Duplechin
Geologist Supervisor
Injection and Mining Division
Office of Conservation
P.O. Box 94275
Baton Rouge, Louisiana 70804-9275

TOPIC: 10-YEAR 24-HOUR PRECIPITATION EVENTS

INQUIRY: Both state and federal SMCRA regulations require sedimentation ponds be designed to
treat or contain a 10-year 24-hour event. Has there been any policy developed, either by OSM or
a state regulatory authority concerning intense, short rainfall events, such as having 25% of the
10-year 24-hour event fall in 30 minutes?

SEARCH RESULTS: Research consisted of a survey of IMCC members and the use of COALEX
and LEXIS. IMCC members who responded to the survey stated that they did not have a policy
for intense short rainfall events. Three Interior administrative decisions were identified that
provide OSM's opinions on exemptions to effluent limitations resulting from intense precipitation
events. Also identified were two EPA and one OSM Federal Register preambles to relevant
regulations.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

   IMCC member states were contacted via facsimiles. Those who responded to the survey stated
that they had no policy regarding short term, intense rainfall events. All followed the SMCRA/EPA
regulations. Illinois indicated that, as a result of problems that state experienced several years
ago with such rainfall events, they considered making changes to their regulations; changes
which would be made in conjunction with ILEPA. However, because the spring and summer
storms bring heavy but isolated rainfall, Illinois determined that record keeping would be too
difficult to maintain and monitoring too difficult to verify. Therefore, they have not gone forward
with new rules to provide operators with exemptions for short intense rainfall events.

ISLAND CREEK COAL CO., 3 IBSMA 383, 88 I.D. 1122 (1981).
   HEADNOTES: "Entitlement to an exemption from the application of effluent limitations to
discharges from a sedimentation pond resulting from a precipitation event is conditioned on a
demonstration that the sedimentation pond was constructed and has been maintained to contain
or treat the volume of water which would run off into the pond during a 10-year 24-hour or
greater precipitation event."

TURNER BROTHERS, INC. v OSM, IBLA 86-243 & 86-245, 103 IBLA 124 (1988).
   Footnote 4: "An operator is not required to protect against all conceivable events which might
cause surface drainage to leave a permit area, but is required to protect against a reasonable
foreseeable range of events which are defined in the regulations as construction standards.
Sedimentation ponds are required to contain or treat a 10-year 24-hour precipitation event.... It
would be incongruous to establish a standard requiring protection against a specific range of
events, but then, when a diversion structure or sedimentation pond meeting the standards is
breached or overflows, hold the operator responsible because it is assumed that there could be
sufficient precipitation to allow surface water to reach the permit boundary. Such an assumption
is tantamount to establishing a standard under which every operator is in continual violation of
the regulation because, whatever the design and construction of a diversion structure or
sedimentation pond, assuming sufficient rainfall, there could be a breach or overflow and water
would flow off the permit area."

TENNESSEE CONSOLIDATED COAL CO. v OSM, IBLA 95-81, 141 IBLA 105 (1997).
   HEADNOTES: "The statement  best technology currently available' in 30 C.F.R. sec. 816.45(a)
does not impose strict liability upon an operator. An operator is not required to protect against all
conceivable events which might cause surface drainage to leave a permit area, but is required to
protect against a reasonable foreseeable range of events which are defined in the regulations as
construction standards. The reasonable foreseeable standard for design intended to protect
against flooding and resultant damage to life and property has been clearly stated in 30 C.F.R.
sec. 816.43(c)(3)."

50 FR 41296 (OCTOBER 9, 1985).  Coal Mining Point Source Category: Effluent Limitations
Guidelines and New Source Performance Standards.  EPA: 40 CFR Part 434.  Final Rule.
   The preamble to the final rule discusses "controlled surface mine drainage", non-controlled
surface mine drainage", "alternate precipitation limitations", etc.

47 FR 45382 (OCTOBER 13, 1982).  Coal Mining Point Source Category: Effluent Limitations
Guidelines for Existing Sources and Standards of Performance for New Sources.  EPA: 40 CFR Part
434.  Final Rule.
   This is enclosed for background.

59 FR 53022 (OCTOBER 20, 1994).  Surface Coal Mining and Reclamation Operations; Permanent
Regulatory Program; Performance Standards; Permanent and Temporary Impoundments.  Final
Rule.
    This, also, is enclosed for background.



ATTACHMENTS
A.   ISLAND CREEK COAL CO., 3 IBSMA 383, 88 I.D. 1122 (1981). 

B.   TURNER BROTHERS, INC. v OSM, IBLA 86-243 & 86-245, 103 IBLA 124 (1988).

C.   TENNESSEE CONSOLIDATED COAL CO. v OSM, IBLA 95-81, 141 IBLA 105 (1997).

D.   50 FR 41296 (OCTOBER 9, 1985).  Coal Mining Point Source Category: Effluent Limitations
     Guidelines and New Source Performance Standards.  EPA: 40 CFR Part 434.  Final Rule.

E.   47 FR 45382 (OCTOBER 13, 1982).  Coal Mining Point Source Category: Effluent
     Limitations Guidelines for Existing Sources and Standards of Performance for New
     Sources.  EPA: 40 CFR Part 434.  Final Rule.

F.   59 FR 53022 (OCTOBER 20, 1994).  Surface Coal Mining and Reclamation Operations;
     Permanent Regulatory Program; Performance Standards; Permanent and Temporary
     Impoundments.  Final Rule.


Research conducted by: Joyce Zweben Scall