2015-09-22_HYDROLOGY - M1986079

• Permit No: M1986079
• IBM Index Class Name: HYDROLOGY
• Doc Date: 9/22/2015
• Doc Name: Sub Water Supply Plan
• From: DWP
• To: DRMS
• Email Name: TOD
• Media Type: D
• Archive: No

DEPARTMENT OF NATURAL RESOURCES
0)" ' DIVISION OF WATER RESOURCES
September 17, 2015
Mr. Rick Parsons, P.E.
Parsons Water Consulting, LLC
4729 W 32,d Ave
Denver, CO 80212
Re: MEtG Substitute Water Supply Plan (WDID 0202503)
MEtG Pit, DRMS No. M-1986-079. (WDID 0203063)
Water Division 1, Water District 2, Weld County
Approval Period: April 1, 2015 - March 31, 2016
Contact phone number for Mr. Parsons: [phone]
Dear Mr. Parsons:
John W. Hickenlooper
Governor
Mike King
Executive Director
Dick Wolfe, P.E.
Director/State Engineer
1�7
vSEP 2 2 2015
DIVISION OF RECLAMATION,
MINING AND SAFETY
We have reviewed your letter dated January 27, 2015 requesting a renewal to the
Substitute Water Supply Plan ("SWSP") for the above mentioned gravel pit. The current SWSP
was approved on May 16, 2014 and expires on March 31, 2015. The required $257 fee to renew
an SWSP has been submitted (receipt no. 3668444).
Plan Operation
The MEtG Pit (aka Polly Mann Pit) was previously operated by Lafarge West, Inc. On May
12, 2011, the Division of Mining, Reclamation, and Safety ("DRMS") approved a succession of
operators from Lafarge to Mann Resources LLC ("Applicant") for this operation. Mann Resources
is now the permitted operator of this Pit and has assumed all reclamation responsibilities for the
site. Mining has ceased and the only remaining work to be done is reclamation. The current
plan is to backfill the exposed groundwater within the next 3 to 5 years, depending on the
availability of suitable backfill material. The exposed water surface has varied significantly
since mining commenced on the site. In addition to exposing ground water, urban runoff is
diverted from the up -gradient Dunes subdivision through culverts and into the gravel pit site,
and ultimately into the South Platte River. Therefore the water level can fluctuate in response
to the frequency and magnitude of runoff events. A precise record of the exposed ground water
surface area was not kept by the original gravel pit operator. The Applicant's consultant
analyzed various records including seven aerial photographs from 2003 through 2012. These
records showed a maximum surface area of 62.2 acres in May 2003 and a minimum surface area
of 17.8 acres in July 2005. More recently the exposed area was 21.4 acres in August 2011 and
27.57 acres in May 2012. In the 2013 SWSP, evaporative depletions were estimated based on an
assumption of a steady exposure of 27.57 acres as supported by the August 2011 and May 2012
aerial survey, and is consistent with recent trends of the ground water surface area, and in 2014
SWSP evaporative depletions were estimated based on a surface area of 23.43 acres. Backfilling
at the site over the last year has reduced the exposed water surface area to a total of
approximately 20.83 acres. Therefore for the purpose of this SWSP evaporative depletions were
estimated based on the current exposed area of 20.83 acres. Although the operational plan is to
Office of the State Engineer
1313 Sherman Street, Suite 818 • Denver, CO 80203 • Phone: [phone] • Fax: [phone]
www.wa tenstate.co.us