2013-05-22_INSPECTION - M1979097

• Permit No: M1979097
• IBM Index Class Name: INSPECTION
• Doc Date: 5/22/2013
• Doc Name: Response
• From: Hart Environmental
• To: DRMS
• Inspection Date: 4/25/2013
• Email Name: ECS
• Media Type: D
• Archive: No

Mr. Jared Dains May 17, 2011
Middle Poudre Combined Plan - Lafarge West, Inc. Page 3 of 9
Computation of the net evaporation during any time that the pit is not completely covered by ice
shall be determined as the pro -rata amount of the monthly gross evaporation rate distribution amount
identified in the State Engineer's General Guidelines for Substitute Supply Plans for Sand and Gravel
Pits, subtracting the pro -rata amount of the effective precipitation for that period.
Based on the Division 1 Water Court decision in case no. 2009CW49, the replacement of evaporative
depletions is not required for ground water exposed to the atmosphere prior to January 1, 1981 through open
mining of sand and gravel, regardless of whether open mining operations continued or were reactivated on or
after that date. The Water Court effectively held that Senate Bill 120 of 1989, as amended in Senate Bill 93-
260, exempted all pre -1981 exposed ground water regardless of whether open mining operations continued
or were reactivated on or after January 1, 1981. Accordingly, for the 38.9 acres (25 acres exposed prior to
January 1, 1981 and 13.9 exposed after December 31, 1980) of ground water currently exposed at the
East Rigden Pit site, replacement of evaporative depletions is only required from the 13.9 acres exposed
after December 31, 1980. Also, for the 66.7 acres (9.2 acres exposed prior to January 1, 1981 and 57.5
exposed after December 31, 1980) of ground water currently exposed at the Weitzel Pit site,
replacement of evaporative depletions is only required from the 57.5 acres exposed after December 31,
1980. The areas exposed prior to 1981 at the East Rigden Pit and the Weitzel Pit is shown on the
attached maps. The exemption from augmentation requirements for the pre -1981 area is tied to
the physical location identified on the map for each site and may no longer be re- allocated to
other areas of ground water exposure within the gravel pits permit boundaries.
Depletions
The depletions resulting from evaporation, water lost in product, dust control and concrete batching
are shown in Table B below:
TABLE B - DEPLETIONS
*0.09 acre -feet for drinking and sanitary purposes within an onsite office, which water returns through a septic
system and is assumed to be 10 % consumptive
Evaporation
Product
Dust
Total
Total
Current
New
Site Name
Loss
Moisture
Control
Depletions
Lagged
Well
Permit
(ac -ft)
Loss
(ac -ft)
(ac -ft)
(ac -ft)
Permit
Requ i r e d ?
ac -ft
East
32.89
I
0.00
1.14
34.03*
33.40
53509 -F
No
Rigden Pit
Three Bells
74.29
15.45
(525,000
2.10
91.85
89.08
64818 -F
No
Pit
tons)
Weitzel Pit
126.79
0.00
0.00
126.79
146.85
64642 -F
No
Kyger Pit
23.66
0.00
0.00
23.66
22.81
53502 -F
No
Port of
56.91
0.00
0.00
56.91
61.39
60890 -F
No
Ent Pit
Shields
1.61
0.00
2.10
3.71
11.85
65095 -F
No
Mine
Total
316.15
15.45
5.34
336,95
365.11
*0.09 acre -feet for drinking and sanitary purposes within an onsite office, which water returns through a septic
system and is assumed to be 10 % consumptive