Attach-4-Soil Investigation .pdf
PDF 2 MB Posted
- Attached to
- CO-MONTE VISTA NWR SEPTIC REPLACEMENT Federal contract opportunity
- Solicitation number
- 140F0121R0004
About this file
This memorandum provides the results of a site and soil evaluation for a septic system replacement project at the Monte Vista National Wildlife Refuge in Colorado. The project involves replacing an existing septic drainfield that serves three residences and one small office building. According to the soil tests, the site features sandy loam topsoil over sandy clay loam subsoil, with a recommended loading rate of 0.35 gallons per square foot per day. The total estimated wastewater flow is 1,364 gallons per day. A new septic tank and drainfield measuring 1,300 feet long by 56 feet wide will be installed to accommodate this flow and meet all required offsets from water sources and structures. The related federal contract opportunity is for the septic system replacement project at the Monte Vista NWR in Colorado, solicited by the U.S. Fish and Wildlife Service.
View the file
Other files for this federal contract opportunity
| File | Type | Posted |
|---|---|---|
| Attach-3-Exisiting Drawings.pdf | ||
| Attach-7-Past Performance and Clauses.pdf | ||
| Sol_140F0121R0004.pdf | ||
| Attach-2-Specifications.pdf | ||
| Attach-6-DBA Min. Wage Rates.pdf | ||
| Attach-5-Price Sheet.xlsx | XLSX spreadsheet | |
| Attach-1-Drawings.pdf |
On GovTribe
Work with this file on GovTribe
- Download the original file
- Contacts named in this file
- Similar government files
- Ask GovTribe AI about this file
Text version
United States Department of the Interior
FISH AND WILDLIFE SERVICE
Mountain-Prairie Region
IN REPLY REFER TO:
BA/EN BID INVI
Mail Stop 60190
Project 21-012
Memorandum
To: Suzanne Beauchaine, Project Leader, Monte Vista NWR
From: Michael Wandersee, PE, Engineering Department
Subject: Site and Soil Evaluation Memo – Replace Septic System (21-012) at the Monte Vista
NWR, Rio Grande County, Monte Vista, CO
This memo addresses the site and soil evaluation based on the State of Colorado requirements.
SOIL INVESTIGATION
A site investigation was conducted on 11/11/2020. The site location is at 6120 CO-15, Monte
Vista, CO. The legal location is T37N R8E S6 W¾N½. Please be aware that the regulation agency is Rio Grande Building Department. Photo 1 shows the test pit locations and surrounding structures as it relates to the new septic system. No wells are located on the immediate property within the required offsets. Please be aware that the treatment system will be located in the same, or slightly larger, footprint of the existing system.
Photo 1: Test Pit and Site Location
A ribbon test was conducted at at north and south test pits. Photo 2 and 3 shows the test pits.
MAILING ADDRESS: STREET LOCATION:
Post Office Box 25486 134 Union Blvd.
Denver Federal Center Lakewood, Colorado 80228-1807
Denver, Colorado 80225-0486
Photo 2: North Pit
Photo 3: South Pit
The soil profiles were the same for north and south pit. It was discovered that the water and water mark in the pictures is from the existing drainfield and not groundwater.
The soil profile was:
0-6 inches sandy loam
6-40 inches sandy clay loam
This result was compared to the NRCS Site Soil Survey website. Photo 4 shows the map from this website.
Photo 4: NRCS Soil Survey
The NRCS designates Sb as San Arcacio sandy loam, saline.
The soil profile was:
0-8 inches sandy loam
8-25 inches sandy clay loam
25-60 inches very gravelly sand
The profiles are very similar. The design will use the test pits because the drainage rate is less than the NRCS website. Please be aware that the existing footprint soil will be completely removed and be replaced with fine sand that creates a large storage capability.
PROJECT SITE
Photo 5 shows that the topographic map from Google Earth. The site is flat and overland flow is a minimal risk.
Photo 5: Topo of Site with Yellow Pin
A well is located on site. The drinking potable water well is located approximately 100 feet from the drainfield system and septic tank. The offset requirements of the site is as follows:
1. Septic tank
a) 50 feet spring well
b) 10 feet potable water supply
c) 10 feet from irrigation lateral
d) 50 feet from lake, water course, irrigation ditch, stream, and wetland
e) 10 feet from dry gulch, cut ban, and fill area
2. Sewer Lines
a) 50 feet spring well
b) 5 feet potable water supply
c) 10 feet from irrigation lateral
d) 50 feet from lake, water course, irrigation ditch, stream, and wetland
e) 10 feet from dry gulch, cut ban, and fill area
f) If these offsets are not possible to meet with the system expectations, the alternative method may be used as described in the drawings.
3. Drainfield
a) 100 feet spring well
b) 25 feet potable water supply
c) 20 feet from basement
d) 10 feet from non-basement structures
e) 25 feet from irrigation lateral
f) 50 feet from lake, water course, irrigation ditch, stream, and wetland
g) 25 feet from dry gulch, cut ban, and fill area
All components will meet this offset requirements, as shown in the drawings. The drawings provide required offsets. The drinking potable water well is the only item of concern. The drinking water potable water well is approximately north of the existing drainfield that can be seen in Photo 1 and 4.
DRAINFIELD AREA
The calculated area is based on desired TL1 treatment and the flows of the attached buildings.
SEPTIC DESIGN FROM CHAMBERS
Soil Type (3) Sandy Clay Loam TL1 0.35 gal/d/ft^2
Wastewater Flow
Office 14.2 gal/day 3 employees, one bathroom, and one sink; peak 10 people per day
Storage 0 gal/day no flow
Residence 1 450 gal/day 3 bedrooms
Residence 2 450 gal/day 3 bedrooms
Residence 3 450 gal/day 3 bedrooms
Total Flow 1364.2 gal/day
Surface Area 3897.714 ft^2 Chamber Width 3 ft Total Length Required 1299.238 ft Rounded Length 1300 ft
The drainfield system requires an impact of 1300 feet long. Each leg of drainfield will run 100 feet, totaling 13 legs. The legs will have a centerline distance of separation of 5 feet; therefore, the total width of the area will be 56 feet.
If you have any questions, please contact Michael Wandersee at 303-236-4479.
File details come from the government source that posted it. Updated .