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GARFIELD COUNTY BUILDING AND SANITATION DEPARTMENT
108 Eighth Street, Suite 201
Glenwood Springs, Coloradof 81601
Phone (970) 945-8212
INDIVIDUAL SEWAGE DISPOSAL PERMIT
Permit 417 8
Assessor's Parcel No.
c; (i71-33)-oo-o)9
This does not constitute
a building or use permit.
PROPERTY rI I n
Owner's Name D I l l,(am S PratAtj AlPs� resent Address(oC fS {�afa . (4) C one
Lf ; -2 C P'— GZ15 & lea, cJ f, t
_01(n;- 33a.— bo—o ai
System Location
Legal Description of Assessor's Parcel No
SYSTEM DESIGN
Septic Tank Capacity (gallon)
Percolation Rate (minutes/inch)
Required Absorption Area - See Attached
Special Setback Requirements.
Date
Other
)1S— y
Q2.8(L S
( (iwts0.PC•ce (kJ ctitti, Mgt
Number of Bedrooms (or other)
stt
3,
Inspector
FINAL SYSTEM INSPECTION AND APPROVAL. (as installed)
Call for Inspection (24 hours notice) Before Covering Installation
System Installer
Septic Tank Capacity
Septic Tank Manufacturer or Trade Name
Septic Tank Access within 8 • of surface
Absorption Area
Absorption Area Type and/or Manufacturer or Trade Name
Adequate compliance with County and State regulations/requirements
Other
Date "J - !^ f `D A Inspector a/ I RETAIN WITH RECEIPT RECO
PE
RDS CONSTRUCTION SITE
•CONDITIONS:
1. All installation must comply with all requirements of the Colorado State Board of Health Individual Sewage Disposal Systems Chapter
25. Article 10 C.R.S. 1973, Revised 1984
2. This permit is valid only for connection to structures which have fully complied with County zoning and building requirements. Con-
nection to or use with any dwelling or structures not approved by the Building and Zoning office shall automatically be a violation or a
requirement of the permit and cause for both legal action and revocation of the permit.
3 Any person who constructs,alters, or installs an individual sewage disposal system in a manner which involves a knowing and material
variation from the terms or specifications contained in the application of permit commits a Class I, Petty Offense ($500.00 Iine —6
months in Jail or both).
Yy1
INDIVIDUAL SEWAGE DISPOSAL SYSTEM APPLICATION
OWNER NlilllQNS Prv4C1M'1
�s
ADDRESS !GR,,S. %aru clout Co gY6 35 PHONE 970 - "Ss = 93 77
CONTRACTOR IP-r-Tnadustr!W/
ADDRESS at/71 RiVeT R�P� GT CO VSOS
PHONE 770 • —VGV
PERMIT REQUEST FOR (VNEW INSTALLATION ( ) ALTERATION ( ) REPAIR
Attach separate sheets or report showing entire area with respect to surrounding areas, topography of area, habitable
building, location of potable water wells, soil percolation test holes, soil profiles in test holes (See page 4).
LOCATION OF PROPOSED FACILITY:
Near what City of Town Pa ea C e, Co Size of Lot 1
Legal Description or Address'/ a 85 CRe2/5,ParacL]c Cc7 (a/7/-33,2-oa-e7tO
WASTES TYPE: ( ) DWELLING ( ) TRANSIENT USE
0 ffic •e 5p (/ COMMERCIAL OR INDUSTRIAL ( ) NON-DOMESTIC WASTES
( )OTHER - DESCRIBE ,'�
BUILDING OR SERVICE TYPE:
Number of Bedrooms 'v} Number of Persons /2- 4w/1 -tate emp /o7eks
( ) Garbage Grinder ( ) Automatic Washer ( ) Dishwasher
SOURCE AND TYPE OF WATER SUPPLY: (t ELL ( ) SPRING
If supplied by Community Water, give name of supplier: t"'�`'� el(
DISTANCE TO NEAREST COMMUNITY SEWER SYSTEM: NA
Was an effort made to connect to the Community System?
A site plan is required to be submitted that indicates the following MINIMUM distances:
Leach Field to Well: 100 feet
Septic Tank to Well: 50 feet
Leach Field to Irrigation Ditches, Stream or Water Course: 50 feet
Septic System (septic tank & disposal field) to Property Lines: 10 feet
YOUR INDIVIDUAL SE WAGE DISPOSAL SYSTEM PERMIT W11,1 NOT BE ISSUED WITHOUT
A SITE PLAN.
GROUND CONDITIONS:
Depth to first Ground Water Table 1 C.3 ft (TH-t) � Akft (TN -2) 3 2 ft (T~' 3)
( ) STREAM OR CREEK
u-�
Percent Ground Slope <
TYPE OF INDIVIDUAL SEWAGE DISPOSAL SYSTEM PROPOSED:
2
x
f( SEPTIC TANK ci3 000e( ) AERATION PLANT
( ) VAULT PRIVY ( ) COMPOSTING TOILET
( ) PIT PRIVY ( ) INCINERATION TOILET
VAULT
RECYCLING, POTABLE USE
RECYCLING, OTHER USE
( ) CHEMICAL TOILET( ) OTHER -DESCRIBE
FINAL DISPOSAL BY:
(kyr ABSORPTION TRENCH, BED OR PIT 014 X 1° 3!
UNDERGROUND DISPERSAL
ABOVE GROUND DISPERSAL
OTHER -DESCRIBE
EVAPOTRANSPIRATION
SAND FILTER
WASTEWATER POND
WILL EFFLUENT BE DISCHARGED DIRECTLY INTO WATERS OF THE
STATE? Ate PERCOLATION TEST RESULTS: (To be completed by
Registered Professional Engineer, if the Engineer does the Percolation Test)
rpbl(o Minutes =/ O per inch in hole No. 1 THi F1ii rtes z Yo per inch in hole NO. 3 TH3
Py 1% Minutes 40 per inch in hole No. 2 71/1 Minutes per inch in hole NO.
Name, address and telephone of RPE who made soil absorption tests:
Name, address and telephone of RPE responsible for design of the system: Ji'h 1 L%, ffi e r1
23o9 fiery-1mi? Aa.e, .63; Ga 10-M;417o2VS 907$
Applicant acknowledges that the completeness of the application is conditional upon such further mandatory and
additional tests and reports as may be required by the local health department to be made and furnished by the applicant
or by the local health department for purposed of the evaluation of the application; and the issuance of the permit is
subject to such terms and conditions as deemed necessary to insure compliance with rules and regulations made,
information and reports submitted herewith and required to be submitted by the applicant are or will be represented to
be true and correct to the best of my knowledge and belief and are designed to be relied on by the local department of
health in evaluating the same for purposes of issuing the permit applied for herein. I further understand that any
falsification or misrepresentation may result in the denial of the application or revocation of any permit granted based
upon said application and in legal action for perjury as provided by law.
Signed
SNCI�+dr ✓. (Jargee -e
Date 3/2- 7/0h
(970 a sy3 — 444 p\ , ,Ps)
PLEASE DRAW AN ACCURATE MAP TO YOUR PROPERTY!!
4 feren., c -74ecAn?cr,( Groin, I'no. report. Job No, al/65/
aw( s,-% pea,.
3
Geotechnical
IlEngineering
Group, Inc.
SEWAGE DISPOSAL SYSTEM DESIGN
Office / Warehouse Building
Williams Gas Facility No. 3
County Road 215, South of Starkey Gulch
Garfield County, Colorado
Prepared For:
Williams Production RMT Company
Mr. Eric Miller
P.O. Box 370
Parachute, CO 81635
Job No. 2,164
November 7, 2005
Geotechnical, Environmental and Materials Testing Consultants
Grand Junction - Montrose - Moab - Crested Butte
(970) 2454078 • fax (970) 245-7115 • geotechnicalgroup.com
2308 Interstate Avenue, Grand Junction, Colorado 81505
•
TABLE OF CONTENTS
SCOPE 1
SUMMARY OF CONCLUSIONS 1
SITE CONDITIONS 2
PROPOSED CONSTRUCTION 3
SEWAGE DISPOSAL SYSTEM DESIGN 4
SUBSURFACE CONDITIONS 4
DESIGN CONSIDERATIONS 5
DESIGN CALCULATIONS 6
PROPOSED DESIGN CONSTRAINTS 6
SYSTEM DESIGN 7
SYSTEM INSTALLATION 9
OPERATION AND MAINTENANCE 12
LIMITATIONS 13
FIG. 1 - VICINITY MAP
FIG. 2 - SITE PLAN / LOCATION OF PROPOSED ABSORPTION SYSTEM
FIG. 3 - ABSORPTION FIELD PLAN VIEW
FIG. 4 - ABSORPTION FIELD CROSS SECTION
APPENDIX A - LOGS AND LEGEND OF PROFILE TEST HOLE AND
RESULTS OF PERCOLATION TESTING
C
SCOPE
This report presents the results of a Sewage Disposal System Design for the
proposed septic system to be located at the Office / Warehouse Building of the Williams
Gas Facility No. 3 at County Road 215, south of Starkey Gulch (Parachute Creek) in
Garfield County, Colorado. Our services were conducted to provide design criteria for the
proposed sewage disposal system. The report includes descriptions of subsoil and
groundwater conditions found in one profile test pit, percolation testing results and design
and construction criteria for the proposed sewage disposal system. The report was
prepared from data collected from percolation testing and developed during engineering
analysis and experience with similar conditions. This report was prepared as continuing
services, in general conformance with our Proposal No. 04-101, dated June 4, 2004.
SUMMARY OF CONCLUSIONS
1. Subsurface conditions encountered in the proposed percolation field area
consisted of sandy clay and clayey sand with variable gravelly and silty
lenses noted. Groundwater was found in the area of the absorption field at
depths of 10 to 20 feet. We used a design soils percolation rate of 60
minutes per inch for the proposed system area calculation.
The proposed sewage disposal system for this site is an absorption field.
We recommend a field of 24 feet by 103 feet dimension encompassing an
area of 2,448 square feet. Detailed design, installation, and operations and
Sewage Disposal System Design
Williams Gas FacIllty No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 2,164
maintenance recommendations are included in the text of this report.
3. Geotechnical Engineering Group, Inc. and Garfield County Health
Department should be called to observe and document system installation,
prior to backfill.
4. An area located south- southeast of the proposed system is designated the
"future repair area". This area should be set aside for potential septic
system remediation. In no case should the proposed system area or future
repair area be constructed with a structure or pavement.
SITE CONDITIONS
The subject site was located approximately 4 miles northwest of Parachute,
Colorado, south of Starkey Gulch (Parachute Creek) and west of County Road 215, Fig.
1. The subject site was located in a northwest and southeast oriented valley bottom.
Steeper slopes were noted along the sides of the valley. The subject site was located
north and west of an existing gas production facility on vacant, undeveloped land. Low
indigenous and non -indigenous vegetation was noted across the site. The facility No. 3
site was gently undulating and generally sloped down toward the southwest at 3 to 6
percent (measured with handheld rangefinder and hand level). Northwest -southeast
trending irrigation type risers (dry at the time of our visit) were noted crossing the central
portion of the facility No. 3 site. Smaller gas production structures were noted near the
north, east and west portions of the site. An earth bermed ditch was noted near the north
and east portion of the site. The ditch was approximately 15 to 20 feet wide and 5 to 7
Sewage Disposal System Design
Wllllame Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 2,164
2
feet deep. Water in the ditch was flowing toward the south. An open excavation near the
west portion of the site was 4 to 10 feet wide, more than 180 feet long and approximately
8 to 12 feet deep. The excavation sidewalls indicated clay type soils. Man Camp Road
was southeast of the site; the previously mentioned gas production facility was beyond.
Parachute Creek, undeveloped land and steeper upslopes of the valley sidewalls were
southwest. Undeveloped land was northwest. County Road 215 was north and east of
the site with steeper valley sidewalls beyond. The vicinity sloped down toward the valley
bottom; the valley bottom sloped down toward the southeast at less than 1 percent
(USGS Parachute, Colorado Quadrangle, 1962).
PROPOSED CONSTRUCTION
We understand the proposed construction will contain 2 showers, 2 toilets and 2
lavatories. We understand there will be a maximum of 12 full time employees that will
use the building. The proposed sewage disposal system (SDS) location is shown on Fig.
2. A log of the profile test hole and percolation testing are included in Appendix A. If
proposed construction changes or is different from what is stated, we should be contacted
to review actual construction and our recommendations.
Sewage Disposal System Design
Williams Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 2,164
3
SEWAGE DISPOSAL SYSTEM DESIGN
Subsurface Conditions
Subsurface conditions at the site were investigated by drilling and sampling
nineteen exploratory borings. Borings TH-18 and TH-19 were in the area of the
proposed absorption field. Locations of the exploratory borings are shown in Appendix
A on Fig. 2. Graphic logs of the soils found in the borings and field penetration
resistance tests are presented in Appendix A on Figs. 7 and 8. Subsurface conditions
encountered included up to 67 of sandy clay underlain by clayey gravel to the maximum
depth explored of 78 feet. The sandy clay had clayey gravelly sand and sandy, silty
clay lenses, was medium stiff to very stiff, dry to wet and brown. This soil had an
appearance of ancient landslide / sheet flow type deposition and sulfates noted.
Groundwater was encountered at 15.5, 26 and 32 feet below the ground surface on the
day of drilling in exploratory borings TH-1, TH-2 and TH-16 (respectively).
Percolation Testing
Percolation testing was performed on August 24 and 25, 2005 in percolation holes
P-1 through P-3. A profile boring was observed at TH-19. Locations of profile boring TH-
19 and P-1 through P-3 are shown in Appendix A on Fig. 2. Three percolation holes were
augered to depths of 4 feet below existing grade and prewetted on August 24, 2005.
Sewage Disposal System Design
Williams Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 7,164
4
A small drainage (dry at the time of our visit) was noted more than 100 feet
southwest of the proposed septic area. No other water sources were identified within 300
feet of the area of the proposed septic system. Results of the percolation testing are
included in Appendix A on Figs. 16 through 18.
Subsurface conditions encountered in the profile hole (TH-19) consisted of 8 feet
of sandy clay to the maximum depth explored of 8 feet below the ground surface.
Groundwater was not identified in the profile to the maximum depth observed. We
estimate a high seasonal groundwater level of 7 feet below the ground surface.
Percolation test results ranged between 20 minutes per inch to time intervals which did
not measurably percolate. Groundwater was not identified in the boring to the maximum
depths observed. Many of the percolation readings were 40 minutes per inch. We used
a design percolation rate of 60 minutes per inch in calculations.
Design Considerations
Based on our site observations and percolation testing, we believe an absorption
bed system can perform satisfactorily for the proposed system. Consideration should be
given to the lowest floor level in order to help insure flow without the need for a lift station.
Sewage Disposal System Design
Williams Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Joh No. 2,164
5
DESIGN CALCULATIONS
Calculations and design parameters used to size the absorption field follow:
Proposed Design Constraints
Average flow Calculation
2 showers 14.7 g/p/d x 2 = 29.4 g/p/d
2 toilets 24.8 g/p/d x 2 = 49.6 g/p/d
2 Lavatories 4.4 g/p/d x 2= 8.8 g/p/d
total = 87.8 g/p/d x 12 employees
= 1,053.6 gallons/day
Peak flow = 150% of average = 1,580.4 gallons/day
Design percolation rate = 60 minutes/inch
A = Q r; where,
t = Percolation rate (minutes/inch)
Q = Peak flow
A = Absorption field area
1580.4
A = 5 60 = 2,448 square feet
(Design dimension = 24 x 102 feet = 2,448 square feet)
Sewage Disposal System Design
WIlllams Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 2,164
6
SYSTEM DESIGN
For purposes of design, we estimate a high seasonal groundwater 7 feet below
the ground surface. The gravel absorption bed system should be placed 2 foot below
the existing ground surface.
1. A minimum tank size of 1,976 gallon septic tank is required to accept septic
effluent from the proposed system (based on a minimum detention time of
30 hours). A larger, readily available, tank size may also be used (such as
2,000 gallon). A removable, cleanable septic tank filter should be installed
at the outlet. As discussed above, a gravel absorption bed system is
proposed to discharge septic effluent to the underlying subsoils. The
design absorption field will be 24 feet by 102 feet in lateral dimension and
encompass an equivalent area of 2,448 square feet.
2. A 12" gravel seepage bed will be placed over the absorption area. The
gravel seepage bed shall consist of 1.0" — 2.5" screened rock with
individual aggregate components of uniform size. Four inch perforated
effluent discharge lines will be embedded in the gravel seepage bed with
a minimum of 6" of gravel under, and 2" of gravel over each line. The
bottom of the gravel bed shall be at least 1 foot below the existing ground
surface. Deeper depths may be required.
3. The piping system should consist of two laterals of four inch perforated
effluent discharge lines, 96 feet in length. Details of the system are
included on Figs. 2 through 4, attached.
4. After the gravel seepage bed is installed, synthetic filter fabric (140-200
mesh), hay, or untreated building paper should be placed over the gravel
and the system covered with a soil cap. The soil cap should consist of 18 -
inches to 24 -inches of native soil mounded 5% to promote surface run off
away from the absorption area.
5. Consideration must be given to provide positive drainage away from the
completed absorption field in each direction.
Sewage Disposal System Design
Williams Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 7,160
7
6. Sidewall construction of the soil cap from the perimeter of the absorption
field to the existing ground surface shall consist of:
• removing surface vegetation and scarifying or disking the existing
ground surface under the basal extent of the soil cap sidewall to
enhance subsurface absorption, followed by;
• maintaining a maximum backslope of 3 horizontal to 1 vertical (33%)
from the resulting perimeter elevation to the existing ground surface
to reduce erosion.
All relevant setbacks with respect to the absorption field shall be taken from
the toe of the surface cap rather than the gravel seepage bed.
8. The area located south-southeast of the proposed absorption system is
designated the future repair area, see Fig. 2. The future repair area should
be set aside for potential septic system remediation. In no case should this
area be constructed with a structure. The same set back and grade
requirements apply to the future repair area as the absorption system area.
9. Eighteen inches to 24 inches of soil cover is recommended for all SDS
elements (excepting maximum 8 inches soil cover over septic access ports)
to mitigate frost concerns.
The installer should confirm the feasibility of gravity discharge of sewage effluent
from the residence to the absorption field. If field measurements do not confirm the
design assumptions, gravity discharge of sewage effluent from the existing residence to
the absorption field can not be assured and a lift pump may be required. Please contact
the design engineer and Garfield County Health Department to address any design
modifications necessary for effective operation of the SDS if the above design
assumptions are not upheld.
Sewage Disposal System Design
Williams Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 2,164
8
The installer must also confirm the setbacks from property lines, building
envelopes, and existing easements shown in the attached graphics are maintained.
Additionally, any unknown utility lines, easements, or other adverse conditions disclosed
during construction must maintain the required setbacks. The proposed residence must
be located to maintain required SDS setbacks as well as provide compliance with Garfield
County Planning Department zoning setbacks. Finally, implementation of a repair
absorption field south of the proposed system may require future installation of a lift
station to provide discharge of septic effluent from the tank to the repair absorption field.
SYSTEM INSTALLATION
The owner and system contractor should be aware of and comply with the
following installation and system operation requirements.
1. All installation activities shall be conducted in accordance with Garfield
County Health Department Sewage Disposal System (SDS) regulations. If
at any time during construction, subsurface site conditions are encountered
which differ from the design parameters stated above, construction activities
should stop and the design engineer and Garfield County Health
Department be contacted to address any necessary design modifications.
The system contractor must be approved and licensed by the Garfield
County Health Department for installation of sewage disposal systems.
3. Installation procedures including grade, location, setbacks, septic tank size,
and absorption field size should conform with the attached figures.
Sewage Disposal System Design
Williams Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 2,164
9
Construction activities and system components should not encroach upon
existing easements or utility corridors. A minimum of 6 feet of undisturbed
soil should be maintained between individual absorption elements and the
septic tank and /or adjacent absorption elements. Minimum setbacks for
system components are:
water line
dwellin
unoccupied
bldg. or
structure
Prose lines
subsoil drains
oaen ditch
lined/gated
ditch
solid pipe
ditch
10 feet
10 feet
5 feet
10 feet
10 feet
50 feet
25 feet
10 feet
10 feet
50 feet
25 feet
20 feet
5 feet
10 feet
25 feet
50 feet
25 feet
10 feet
25 feet
50 feet
10 feet
10 feet
10 feet
50 feet
25 feet
10 feet
10 feet
50 feet
4. To help avoid surface flow infiltration and saturation of the new absorption
system, abandonment of flood irrigation within 50 feet of any SDS element
is recommended.
5. All sewer lines and effluent distribution piping should be 4 inches in
diameter, have glued joints, and should looped at termination of discharge.
Septic tank lines should be placed level. All lines discharging sewage from
the residence to the septic tank shall maintain fall of between 1/8 inch and
1/4 inch per foot and shall employ sweep 90's or 2-45's at all turns. Sewer
lines from the dwelling to the septic tank and at least 6 feet from the septic
tank outlet must meet minimum standard ASTM -3034. Sewer lines under
driveways shall always meet minimum Schedule 40 PVC standards and
should be encased with corrugated metal pipe when covered with less than
Sewage Disposal System Design
Williams Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 2,164
10
24 inches of soil.
6. Eighteen inches to 24 inches of soil cover should be maintained over all
SDS components to mitigate freezing of septic effluent (excepting maximum
8 inches cover over septic access ports).
7. The installer should not place fill in the open excavation until inspected and
approved by the design engineer. Additionally, the final cover should not be
placed on sewer lines, septic tank, or the absorption area until the system
has been inspected and approved by the design engineer and the Garfield
County Health Department.
8. The installer should provide 48 hour notice to the engineer and the Garfield
County Health Department for all required inspections.
9. Four inch effluent distribution lines should be embedded in gravel with a
minimum of 6 inches of gravel under, and 2 inches of gravel over each line.
A layer of 1.0 to 2.5 inches screened rock with individual aggregate
components of uniform size should be used. A covering of untreated
building paper, hay, straw, or synthetic filter fabric should be placed on top
of the gravel before placing the surface cap.
10. The system contractor shall be aware of the potential for construction
activities to reduce soil permeability's at the site through compaction,
smearing, and shearing. The following precautions and construction
procedures should be employed during installation to mitigate disturbance
to native soils:
a. Excavation should proceed only when the moisture content of the
soil is below the plastic limit.
b. Excavation and backfill equipment should work from the surface
where at all practical to avoid compaction of the soils at depth.
c. The bottom and sidewalls of the excavation should be left with a
rough, open surface. The appearance should be that of broken or
ripped soil as opposed to a sheared, smeared, or troweled surface.
Any smoothed or smeared surfaces should be removed with a
toothed rake or shallow ripper taking care to remove loose residues
from the bottom of the excavation by hand if necessary.
Sewage Disposal System Design
Williams Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 2,164
11
d. Care should be taken in placing fill materials in the excavation to
avoid damaging the exposed soil surfaces.
OPERATION AND MAINTENANCE
Performance of the subject sewage disposal system will be dependent on suitable
operations and maintenance practices. The owner must understand and accept
responsibility for operations and maintenance of the system. Important factors include:
1. The owner should install a structural barrier if necessary and take
precautions to prevent vehicular traffic, excessive surface watering,
accidental flooding, or other activities in the vicinity of the absorption field
which may compact, saturate, or otherwise alter the subsurface soil
parameters used in designing the septic system.
2. The owner should plant and maintain grass or other shallow rooted cover
crop to prevent erosion and promote evapotranspiration over the absorption
area.
3. The owner should inspect and maintain the required mounding and
drainage away from the absorption area to prevent saturation from
precipitation and surface flows.
4. The owner should inspect and prevent intrusion of burrowing animals and
deep rooted plants into the absorption area.
5. The owner should conduct periodic maintenance of the septic system by
removing accumulated sludge from the septic tank every 3 to 4 years to
prevent clogging of the absorption area. The septic tank filter should be
inspected on a yearly basis, minimum.
Sewage Disposal System Design
Williams Gas Facility No.]
Parachute Creek, Garfield County, Colorado
GEG Job No. 2,164
12
6. The owner should not allow disposal of harmful substances into the subject
sewage disposal system.
LIMITATIONS
Satisfactory performance of a sewage disposal system is dependent on several
factors including subsurface evaluation, design, installation, operation and maintenance
procedures. It is important to understand there is an element of risk inherent with the
performance of each individual sewage disposal system. The design engineer can
provide design measures and recommendations to help mitigate risk. A comprehensive
review by the hearth department is recommended to help mitigate risk. The risks
associated with overall system operation/performance must be understood and accepted
by the owner.
Design notes contained in this report are based on limited subsurface data.
Variations in subsurface conditions not indicated by the test pit are possible.
Subsurface conditions may also change with time. The installation contractor should
observe actual subsurface conditions exposed at the time of excavation. If differing
conditions are suspected, installation should cease immediately. If different soil or
groundwater conditions are suspected, Garfield County Health Department and our
office should be contacted to review conditions and make necessary design changes.
The recommendations contained in the report are also based on information supplied to
Sewage Disposal System Design
Williams Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 2,164
13
GEG by the client. Geotechnical Engineering Group does not accept responsibility for
variation in the assumed design parameters.
The scope of work performed is specific to the proposed construction and the
client identified by this report. Any other use of the data, recommendations and design
parameters (as applicable) provided within this report are not appropriate applications.
Other proposed construction and/or reliance by other clients will require project specific
review by this firm. Changes in site conditions can occur with time. Changes in standard
of practice also occur with time. This report should not be relied upon after a period of
three years from the date of this report and is subject to review by this firm in light of new
information which may periodically become known.
We believe this design was conducted in a manner consistent with that level of
care and skill ordinarily used by geotechnical engineers practicing in this area at this
time. No other warranty, express or implied, is made. If we can be of further service in
discussing the contents of this report or the analysis of the influence of the subsurface
conditions on the design of the proposed construction, please call.
Sewage Disposal System Design
Williams Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 2,164
14
Sincerely,
GEOTECHNICAL
Joh P. Withers,
Principal Engineer
JPW:cb
(3 copies sent)
0 REG/'.
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Sewage Disposal System Design
Williams Gas Facility No.3
Parachute Creek, Garfield County, Colorado
GEG Job No. 2,164
ROUP, INC.
15
Sewage Disposal System Design
Williams Gas Plant No. 3
County Road 215 and Mancamp Road
Garfield County, Colorado
Job No. 2,164 Vicinity Map
Fig. 1
fl
Proposed
Building
Sentic
Tank
Relocate
Dirt Road
50' South
1_1-)
)
Absorbtlopi
/
z//
Future
Repair
Area
Job No. 2,164 Location of Sewage Disposal System Fig. 2
Proposed
Building
1/ 1 11111
Clean Out
Septic Tank`
4" Perforated
PVC Pipe
Job No. 2,164
Looped at ends
6'
102'
24'
Scale: 1" = 20'
Absorption Field
Plan View
Clean out should be
provided every 100
lineal feet.
Fig. 3
12" Seepage Bed
1.0 - 2.5 inch screened rock
4 -inch Perforated Distribution Lines, typical
(6" Gravel under, 2" Gravel over minimum)
Synthetic Filter fabric,
hay or untreated building
paper over gravel
Soil Cap
(mound 5%)
3' - I 1'
Job No. 2,164
24'
Scale 1"=-5'
Absorption Field Cross Section Fig. 4
APPENDIX A
LOGS AND LEGEND OF PROFILE TEST HOLE
AND RESULTS OF PERCOLATION TESTING
TH-1
•
Note: This figure was prepared
based on GEG field and in house
mapping, and is intended to show
exploratory boring locations only.
(TH-2
TH-5
TH•3 �n
TH-13
TH-16
::
Antcipated location of
proposed structures
(typical)
TH-17
T�9 H-18
P-10 O P-3
O
P-2
Legend
• Indicates location of
exploratory borings.
o Indicates location of
percolation testing.
Job No. 2,108 Location of Exploratory Borings
Fig. 2
0
co
m
w
TH-1
elev. 5434'
TH-2
elev. 5444'
TH-3
elev. 5442'
TH-4
elev. 5433'
5450 5450
Anticipated Plant
Finish Grade
elev. 5431' & 5440'
5440
5430
5420 0
5410
5390
5380
5370
5/12
/ 20/12
20/12��- 18/12
6/12
9/12
—/—/(e— 5406
5396
6/12
50/9
50/9
/7/12
8/12
7/12
4/12
5440
5430
5420
5410
4)
a)
c
0
a)
w
5390
5380
5370
Job No. 2108 Logs of Exploratory Borings Fig. 3
m
w
O
>
a)
LT
TH-5 •
elev. 5441'
— 5450
— 5440 —
— 5430
22/12
8/12
7/12
— 5420
— 5410
5400
5390
5380
5370
TH-6
elev. 5432'
TH-7
elev. 5433'
8/12
4/12
77/12
TH-8
elev. 5430'
Anticipated Plant
Finish Grade
elev. 5431' & 5440"
7-1
19/12
16/12
16/12
6/12
21/12
8/12
6/13
6/12
5450
5440
5430
5420 —
5410
5400
5390
5380
50/10 5370
50/10
Job No. 2108 Logs of Exploratory Borings Fig. 4
0)
c
0
m
0
w
d
c
0
a)
w
TH-9 '
elev. 5434'
5450
— 5440
5430
— 5420
5410
TH-10
elev. 5439'
TH-11
elev. 5442'
Anticipated Plant
Finish Grade
elev. 5431' & 5440'
/i
25/12
21/12
/8/12
/,� 7/12
19/12
11/12
14/12
TH-12
elev. 5448'
5450
16/12 5440
8/12
11/12
5430
5420
5410
5400 5400
Job No. 2108 Logs of Exploratory Borings Fig. 5
c
0
0
w
O
0)
C
0
co
0
w
TH-13 •
elev. 5444'
TH-14
elev. 5443'
TH-15
elev. 5339'
TI -I-16
elev. 5442'
5450 5450
Anticipated Plant
Finish Grade
elev. 5440'
5440
5430
5420
— 5410
5400
5390
5380
19/12
12/12
▪ 14/12
23/12
13/12
6/13
15/12
8/12
8/12
24/12
8/12
8/12
11/12
29/12
5440
5430
5420
5410
5400
5390
48/12 –
5380
50/5 _
5370 5370
Job No. 2108 Logs of Exploratory Borings Fig. 6
w
0
w
0
w
0
0
w
5450
— 5440
5430
5420
5410
` TH-17
elev. 5436'
19/12
19/12
8/12
TH-18
elev. 5431'
TH-19
elev. 5429'
Anticipated Plant
Finish Grade
elev. 5431'
21/12
17/12
7/12
9/12
5450-
5440
450-
5440
5430
5420
5410
5400 5400
Job No. 2108 Logs of Exploratory Borings Fig. 7
0
a)
trtsc
0
0
w
Legend
Clay, sandy, Sand, clayey, gravelly and Clay, sandy, silty lenses, medium
stiff to very stiff, dry to wet, brown, sulfates noted, possible ancient
slide deposits. (CL)
Gravel, clayey, dense to very dense, wet. (GC)
Indicates drive sample. The symbol 5/12 indicates that
5 blows of a 140 pound hammer falling 30 inches were required
to drive a 2.5 inch O.D. sample barrel 12 inches.
Indicates bag sample taken from auger cuttings.
Indicates free water level. Numeral indicates number of days
after drilling that measurement was taken.
I Indicates depth at which exploratory boring caved.
Indicates practical drill rig refusal with augering methods. Boring terminated.
Indicates penetration test. The symbol 50/9 indicates that 50 blows of a
140 pound hammer falling 30 inches were required to drive a 2.5 inch
O.D. dynamic cone 9 inches.
Elev. Indicates elevation of ground surfaces at test boring location as obtained
5,434 from topographic map provided by Williams Production and is approximate.
Notes
1. Exploratory borings were drilled and sampled on August 24 and 25, 2005
using a 4 -inch diameter solid stem, continuous flight auger and
a track mounted drill rig.
2. These logs are subject to the explanations, limitations and
conclusions as contained in this report.
Job No. 2,108
Legend of Logs of
Exploratory Borings
Fig. 8
Geotecboleal
'Eagleeerlug
,Groep, Inc.
SATURATION AND PREPARATION
DATE: August 24, 2005
TIME AT START OF SATURATION: 11:30
PERCOLATION TEST
DATE: August 25, 2005
WATER IN BORINGS AFTER SATURATION
Depth to Water
YES X NO
PERCOLATION TEST RESULTS
HOLE
NUMBER
s" Diameter
DEPTH
(INCHES)
TIME AT
START OF
INTERVAL
TIME
INTERVAL
(MINUTES)
DEPTH TO WATER
CHANGE
IN WATER
DEPTH
(INCHES)
PERCOLATION
RATE
(MIN/INCH)
START OF END OF
INTERVAL INTERVAL
(INCHES) (INCHES)
P-1 @ 0'
4" DIA
48"
11:01
10
33.25
33.5
0.25
40
48"
11:11
10
33.5
34.0
0.5
20
48"
11:21
10
34.0
34.25
0.25
40
48"
11:31
10
34.25
34.25
0.0
^"
48"
11:41
10
34.25
34.5
0.25
40
48"
11:51
10
34.5
34.75
0.25
40
* Note * -, : indicates did not percolate during this interval.
Job No. 2,108
Fig. 16
Geoteehnlcal
'Frgineering
,Group, Lae.
SATURATION AND PREPARATION
DATE: August 24, 2005
TIME AT START OF SATURATION: 11:40
PERCOLATION TEST
DATE: August 25, 2005
WATER IN BORINGS AFTER SATURATION
Depth to Water
YES X NO
PERCOLATION TEST RESULTS
HOLE
NUMBER
8' Diameter
DEPTH
(INCHES)
TIME AT
START OF
INTERVAL
TIME
INTERVAL
(MINUTES)
DEPTH TO WATER
CHANGE
IN WATER
DEPTH
(INCHES)
PERCOLATION
RATE
(MIN/INCH)
START OF END OF
INTERVAL INTERVAL
(INCHES) (INCHES)
P-2 @ 0'
4" DIA
48"
11:02
10
33.25
33.5
0.25
40
48"
11:12
10
33.5
33.75
0.25
40
48"
11:22
10
33.75
34.0
0.25
40
48"
11:32
10
34.0
34.25
0.25
40
48"
11:42
10
34.25
34.5
0.25
40
48"
11:52
10
34.5
34.75
0.25
40
Job No. 2,108
Fig. 17
Geotechnieal
Enalneering
1 Group, Lar.
SATURATION AND PREPARATION
DATE: August 24, 2005
TIME AT START OF SATURATION: 11:50
PERCOLATION TEST
DATE: August 25, 2005
WATER IN BORINGS AFTER SATURATION
Depth to Water
YES X NO
PERCOLATION TEST RESULTS
HOLE
NUMBER
8° Diameter
DEPTH
(INCHES)
TIME AT
START OF
INTERVAL
TIME
INTERVAL
(MINUTES)
pEPTH TO WATER
CHANGE
IN WATER
DEPTH
(INCHES)
PERCOLATION
RATE
(MIN/INCH)
START OF END OF
INTERVAL INTERVAL
(INCHES) (INCHES)
P-3 @ 0'
4" DIA
48"
11:03
10
30.25
30.75
0.5
20
48"
11:13
10
30.75
31.0
0.25
40
48"
11:23
10
31.0
31.0
0.0
48"
11:33
10
31.0
31.25
0.25
40
48"
11:43
10
31.25
31.5
0.25
40
48"
11:53
10
31.5
31.5
0.0
co
' Note * m : indicates did not percolate during this interval.
Job No. 2,108
Fig. 18
JOB NO. 2,108
w
m
H
et il
1 i
V yL
0 d
iu C 0
E C V
0 'Aev
G7 AIM
SUMMARY OF LABORATORY TEST RESULTS
W
0}
J
Q
CO
U
T
C
CO
>.
(0
U
Clay, sandy (CL)
Clay, sandy (CL)
Clay, sandy (CL)
U
T
C
CO
T
0)
U
'Clay, sandy, silty (CL)
Clay, sandy (CL)
Clay, sandy (CL)
U
T
C
Ute)
T
0)
00
U
T
C
N
T
co
Clay, sandy (CL)
Clay, sandy (CL)
1 Clay, sandy (CL)
U
T
9C
0
T
0)
U
LClay, sandy (CL)
Clay, sandy (CL)
,Clay, sandy, silty (CL)
WATER
SOLUBLE
SULFATES
(Ppm)
PASSING
NO. 200
SIEVE
(%)
O)
1-
K)
co
0
co
Swell / Consolidation
CONFINING
PRESSURE
(PSF)
O
o-
Na
in
N
SWELL
(%)
Laboratory Testing in Progress l
Laboratory Testing in Progress
0.
+
Laboratory Testing in Progress
(O
O
+
+0.6
N
O
+
Atterberg Limits
PLASTICITY
INDEX
(%)
11)
0
D
_)2o
dJ-
J
co
23
DRY
DENSITY
(PCF)
I.--
0
107
N
0
O
0
0)
.-
0
0
102
N
r
107
103
114
109
0
O
Cr)
r
r
r
T
NATURAL
MOISTURE
(%)
20.8
17.9
20.8 1
N
00
0
202 f
u]
r
0)
ao
M
22.4
N
co
(•1
u]
(0
n
O
m
N
00
N
6
19.8
DEPTH
(FEET)
N
Q)
n
n
O)
V
Q)
V
O)
N
O)
V
2
N
V
L 9
CD
N
J
O
=
H
e;1
1—
c7
1-
q
F-
'9
1-
( 4
1-
r
H
O7
H
O)
H
O
r
JOB NO. 2,108
w
-J
m
H
Wd
1ea
-
vE
eco
A CVit
'i A
SUMMARY OF LABORATORY TEST RESULTS
W
a
J_
O
co
Clay, sandy (CL)
Sand, clayey, gravelly (SC)
Clay, sandy (CL)
Clay, sandy (CL)
Clay, sandy (CL)
Sand, clayey, gravelly (SC)
Sand, clayey (SC)
Clay, sandy, gravelly (CL)
Clay, sandy (CL)
Clay, sandy (CL)
Clay, sandy, silty (CL)
Clay, sandy (CL)
WATER
SOLUBLE
SULFATES
(Ppm)
PASSING
NO. 200
SIEVE
(%)
V
N
30
(D
V
51 1
O)
Ill
O)
(.0
Swell / Consolidation 1
CONFINING
PRESSURE
(PSF)
O
O N
1,000
1,000
O
Ul
0
O
SWELL
(%)
N
+
Laboratory Testing in progress - -
V
o
N.
o
t()
+
(n
o
Laboratory Testing in Progress
Atterberg Limits
F
UX
a
� Z 0 a
5—
o
r
0I-
n�i'
%, J
J
V
N
co
N
} L.L
ix U
o Z a
0
O)
'-
el
0
r
to
0
114 1
84
114
to
r
a)
0
V
r
I-
0
N-
0
NATURAL
MOISTURE
(%)
(O
n
N-
r
m
co
ni
26.0
4.5 1
til
n
co
4
f`
O
m
e --
tri
10.9
16.4
M r
H
WO)
11.1
0 LL
cn
O)
O)
O
a)
4
0)
N
N
O)
•V
to
LllN
J
0
T
H
I—
O
F
V
1--
(0
F
(0
I—
n
H
N
I—
N
0
a
1
G of chnical
IEngin ering
Group, Inc.
September 29, 2006
Williams Production RMT Company
Mr. Tom Fiore
P.O. Box 370
Parachute, CO. 81635
Subject: Sewage Disposal System
"As Built" Field Drawing
Gas Plant No.3, County Road No. 3, South of Starkey Gulch
Parachute, Colorado
Job No. 2,164
As requested, a Geotechnical Engineering Group, Inc. (GEG) representative met with the
contractor representative to observe septic system installation at the subject site on September 25, 2006.
At the time of our observation, the absorption system was observed to be installed. Field measurements
indicated the installation was completed in conformance with the "Sewage Disposal System Design"
prepared for the subject site by GEG dated November 7, 2005. A field "as built" drawing showing the
system installation is attached as Fig. 1.
We appreciate the opportunity to provide professional services. When we can be of further
service, please call.
Sincerely, NR'P REG/s),
n1T+
GEOTECHNICAL ENGI �RI'P' !^'h1'?ra=ffl�
•
30324
s •
-O
iI�
`l4-l•LP i
John P. Withers, P.E. �p •. •
Principal Engineer "ct ..••••••••:.:0.1�'
SIONALS7
JPW:jpw
(1 copy sent)
2 cc:
Phil Vaughan Construction Management
Mr. Phil Vaughan
1038 County Road 323
Rifle, CO 81650
rtIvE,
C
ARF
G 9 2006
sofco
pL41NN NGY
Geotechnical, Environmental and Materials Testing Consultants
(970) 245-4078 • fax (970) 245-7115 • geotechnicalgroup.com
2308 Interstate Avenue, Grand Junction, Colorado 81505
Cleanout —
177'
22°
172' 116'
145°
Williams 3
Gas Plant
Existing
Building
/
/v////////////////////////////
L 3.5'
f 27'
53'
79'
Cleanout
258'
27
100'
_24'
Job No. 2,164
241'
Lat: 39° 29.241'
Long: 108° 06.750'
Elev: 5077'
Absorption System
"As Built" Drawing Fig. 1
To
co