REPORT OF THE COMMISSION

This cause came on for hearing before the Commission on May 16, 1972 at 1 p. m., in Room 132, State Services Building, Denver, Colorado, after giving Notice of Hearing as required by Law, on the Commission's own motion, for the purpose of determining rules and regulations governing the construction, maintenance, and operation of retaining pits in an area including Morgan County and parts of Washinton and Weld Counties.

FINDINGS

The Commission found as follows:

1. That due notice of the time, place, and purpose of the hearing has been given in all respects as required by law.

2. That the Commission has jurisdiction over the subject matter embraced in said Notice, and of the parties interested therein, and jurisdiction to promulgate the hereinafter prescribed order.

3. That the area which includesMorgan County and parts of Washington and Weld Counties, is described as follows:

Morgan County T. 4S, R. 53W

All Lands Sections 5 thru 8 and 17 thru 19

Washington County T. 5S, R. 54W

T. 1S thru 4S (incl) Sections 1 thru 10, 17 and 18 54W thru 56W (incl) T. 5S, R. 55W All Sections Sections 1 thru 24, 26 thru 33 T. 1S, R. 53W T. 5S, R. 56W W1/2 except Section 33 All Sections T. 2S, R. 53W T. 1N R. 53W Sections 4 thru 9, 16 thru 21, 30, and 31 Sections 2 thru 10, 16 thru 21 28 thru 32 T. 3S, R. 53W T. 1N, R. 54W Sections 6 thru 8., 17 thru 20 and 29 thru 32 All Sections

T. 2N, R. 53W T, 5N, R. 5 IW

Sections 1 thru 35 Sections 4 thru 8, 17 thru 19 30 and 31 T. 2N, R, 54W T. 5N.4 R.52W All Sections All Sections

T. 3N, thru 5N R. 53W thru 54W Weld County

All Sections T. 6N, R. 61W thru 67W

T, 3N, R, 52W All Sections

Sections 1 thru 12, 16 thru T. 7N thru T. 12N 20, and 29 thru 32 R,. 56W thru 67W

T. 4N, R. 51W All Sections

Sections 6, 7, 18, 28 thru 32 T. 4N, R. 52W

All Sections

4. That the Pierre Shale formation, considered the bedrock formation, underlies the above-described area and is exposed in western Washington County- and along drainages in many parts of Morgan County. The Fox Hills Sandstone, where present, overlies the Pierre Shale and outcrops along some drainages in eastern Weld County and northern Morgan County. The maximum thickness in the area is about 350 feet. The formation also outcrops in an area of southwes tern Morgan County which is part of the North Kiowa-Bijou Creek Basin. The Laramie formation overlies the Fox Hills and is exposed in much of southwestern Weld County and northwestern Morgan County. It consists of shales, silty sands, clays, and coal seams as well as some sandstone beds. It can be as thick as 600 feet in some areas. Overlying the Laramie is the White River Group (Brule and Chadron formation). It consists of silt, fine sands, and grav el deposits as well as having some local fracturing, and is exposed in the northern and eastern parts of Weld County. Thickness varies widely from place to place and maximum is about 600 feet. The Arikaree formation, consisting of medium to fine grain sandstone, overlies the White River. It is exposed in a small area of northwestern Weld County, and is not known to have a maximum thickness of more than 80 feet. The Ogallala formation, next in sequence in geological age, is found only in the northwestern and northeastern part of Weld County and continues east along the State boundary into Logan County. The formation consists of sands, silt, and clay as well as gravel deposits. Thickness probably does not exceed 180 feet. Overlying the area in various parts are the alluvium deposits. Such deposits are found mainly in the South Platte River Valley and tributaries. Dune Sand deposits have been mapped in the south central part of Weld County and in parts of Morgan County.

5. That each of the formations described contain aquifers. The aquifer in the alluvial deposits often yields moderate to large quantities of water to stock and domestic and irrigation wells, and is considered the principal aquifer in the area. The aquifers in the formations below the alluvial deposits yield small to moderate quantitates of water to wells in the area. The Pierre Shale is considered a poor source of water, but there are some wells drille d to this formation. The Fox Hills aquifer is of more im ortance in that area which is part of the North Kiowa-Bijou Basin. The aquifers of the White River group yield adequate amounts of water to small capacity wells in the area mainly from the fractured zones as well as from locally "porous zones" or channel deposits. The Arikaree formation is not known to yield but very small amounts of water and is not considered a potential source. The dune sands are not considered a source for water in the area. They are, however, highly permeable and allow rapid downward percolation of applied water.

6. That while the formations below the alluvial deposits may contain clay, shale beds, or coal seams which form impermeable barriers of sufficient thickness to prevent the seepage of oil field waters from entering the deeper underlying aquifers, special precautions must be taken to prevent seepage from a retaining pit, located on the outcrop of the formations or on the alluvium, from reaching aquifers contained in such f ormations or alluvium.

7. That the aquifers contain a very substantial quantity of water in storage. The water in the aquifers of the alluvial deposits generally moves in the direction following the stream course and the water in the deeper aquifers generally moves in a direction toward the South Platte River. The water in these aquifers is generally of good quality and, because of its great need for domestic and public supply, should be protected.

8. That the produced water from the "J" Sand in this area is of lower concentration of total solids than the water from the "D" Sand. The total dissolved solids of the "J" Sand produced water range from approximately 900 to 9, 000 parts per million. The "D" Sand produced water quality range is from approximately 4, 000 to 18, 000 parts per million.

9. That accepted standards for water quality have been established by the Water Pollution Control Commission for domestic use as less than 500 parts per million of total dissolved solids, and less than 3, 000 parts per million for livestock and irrigation purposes. These limits are guidelines of acceptable water use depending on varying circumstances and tolerances established by people, livestock, and types of crops.

10. That as indicated in the testimony of the previous hearing on the Northern High Plains Ground Water Basin, a serious oil reserve deficiency situation exists in the United States today and will become more serious in the future. An average of less than 40% of the oil in a reservoir is recovered by present known methods and an effort should be made to keep small fields producing so they will be available for treatment by more sophisticated recovery met hods being developed.

11. That since oil field retaining pits are attractive to and used by ducks, geese, and other wildlife in the area, such pits should be kept free of even small accumulations of oil.

The Oil and Gas Conservation Commission has the responsibility and authority to prevent destruction of wildlife from oil field sources.

ORDER

NOW, THEREFORE, IT IS ORDERED that the following shall apply to the area as described in Finding 3 herein.

1. That the Director be authorized and directed to approve on behalf of the Commission:

a.All pits designed and located in accordance with and fully complying with the Commission's regulations (Rules 325 and 326).

b.All pits meeting the standard of (a) above except where the pit is not lined, and applicant supplies substantial evidence to the Director that the quality of the produced water is substantially the equivalent of the underlying aquifer.

c.All pits located in the Pierre Shale, the Laramie formation, or in a member of the White River Group where the pit otherwise meets the standards of (a) above except where the pit is not lined, but is located in or over a stratum of such impervious nature and of such thickness that it would be reasonable to expect that seepage from such pits could not reach any underlying aquifer and also where it would be reasonable to expect that any horizontal flow o f the produced waters through formations above such impervious stratum could not reach any nearby wells or other waters of the State.

d.All pits located in the dune sands, alluvium and other surficial deposits as well as in -the other formations not mentioned in (c) above and meeting the standards of (a) above except where the pit is not lined and it is clearly established by substantial evidence or percolation tests that seepage will not reach any underlying aquifer or other waters of the State.

2. That applicant may, in the event a premature abandonment of producing oil or gas wells will result in not being able to comply with Paragraph 1 hereinabove, submit to the Director a complete economic statement of the situation, including estimates of lining the pit or other methods of reasonably protecting the pit from seepage and oil accumulations, consideration being given to the volume of water being handled, and estimates as to the production and r eserves that may be lost in primary and secondary recovery methods. The Director shall then submit such application to the Commission for its final action.

3. That applicant may, in the event he believes that produced water from his well or wells is of a quality usable for stock or irrigation purposes and that a strict enforcement of Paragraph 1 hereinabove will prevent such use, submit such test result and materials substantiating such need and a proposed plan showing how such use can be accomplished. The Director shall then submit such application to the Commission for its final action.

4. Notwithstanding Paragraphs 1. 2, and 3 hereinabove, where it appears to the Director that produced water from a field, fields, or combination of wells should be disposed of underground, he shall notify the Commission of such recommendation and notify the operators in the affected areas. The operators shall have a maximum of one hundred twenty (120) days to continue the use of pits during which time they shall be required to submit a plan for undergrou nd disposal of the produced water.

5. In the case of any other application not requiring action under the foregoing paragraphs, the Director shall submit such application to the Commission with his recommendation for final action.

6. Any applicant desiring a hearing before the Commission, either before the Director makes any recommendation to the Commission, or after such recommendation, shall be entitled to such hearing upon request. If the hearing is desired because of the Director's recommendation, such request shall be made within thirty (30) days of the Director's recommendation.

IT IS FURTHER ORDERED, that the Commission expressly reserves its right., after notice and hearing to alter, amend, or repeal any and/or all of the above Order.

ORDERED this 16th day of May 1972. OIL AND GAS CONSERVATION COMMISSION OF THE STATE OF COLORADO

By Frank J. Piro, Secretary