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HomeMy WebLinkAboutSubsurface Investigation and OWTS Design 05.14.16 May 14, 2016 Project No. C1212 Kirk Williams kirkwilliams@hangar45.com Subsurface Investigation and Onsite Wastewater Treatment System Design 3-Bedroom Residence + Future 2-Bedroom ADU 4 Red Wing Lane Garfield County, Colorado Kirk, ALL SERVICE septic, LLC performed a subsurface investigation and completed an onsite wastewater treatment system (OWTS) design for the subject 5.01-acre property located outside of Carbondale, in an area where OWTSs are necessary. Legal Description: Section: 13 Township: 7 Range: 88 Subdivision: HAWK RIDGE SUBDIVISION Lot: 4 SITE CONDITIONS A 3-bedroom, single-family residence presently exists on the property. A future, 2-bedroom additional dwelling unit (ADU) is proposed. The existing residence is currently served by an existing OWTS; however, there is a desire to upgrade the existing system by creating an alternating soil treatment area (STA). The existing OWTS is working properly and will be integrated into the new OWTS design. The existing residence is served by a community water system. The future ADU will also be served by the community water system. The water line runs from the western property boundary, southeast to the existing residence. A minimum 25-foot setback must be maintained from the new STA to the water line. We believe the water line crosses the existing sewer line that had been previously installed from the approximate location of the future ADU to the existing septic tank. We do not know if either line is encased, as they are both existing. The proposed STA location slopes at approximately 7.5% to the west. The existing STA is located just up gradient (east) of the proposed STA. The area is covered with native grasses. SUBSURFACE The subsurface was investigated on May 14, 2016 by digging two soil profile test pit excavations (Test Pits). A mini-excavator was used to excavate the test pits. A visual and tactile soil analysis was completed by Carla Ostberg at the time of excavation.1 The materials encountered in Test Pit #1 consisted of medium brown, moist topsoil to 2-feet, underlain by light brown silt loam (caliche) to 5-feet, underlain by light brown, dense silt loam (caliche) to a maximum depth explored of 8-feet. No bedrock or groundwater was encountered. 1 Carla Ostberg holds a Certificate of Attendance and Examination from the CPOW Visual and Tactile Evaluation of Soils Training. Page 2 The materials encountered in Test Pit #2 consisted of medium brown, moist topsoil to 3-feet, underlain by light brown silt loam (caliche) to 7-feet, underlain by light brown, dense silt loam (caliche) to a maximum depth explored of 8-feet. No bedrock or groundwater was encountered. A sample of the soils was taken from Test Pit #1 at 2.5 to 3-feet below grade. The soil formed a ball and a ribbon less than 1-inch in length before breaking. Soil structure shape was blocky, soil structure grade was moderate, and consistence was friable. STA sizing is based on Soil Type 2, Silt Loam with blocky structure type and moderate structure grade. A long term acceptance rate (LTAR) of 0.6 gallons per square foot will be used to design the OWTS, in accordance with Table 10-1 Soil Type 2 presented in the Garfield County On-Site Wastewater Treatment System Regulations, adopted April 14, 2014. Test Pit #1 Sieved sample Page 3 DESIGN SPECIFICATIONS The existing septic tank and STA will be continue to be utilized. A new septic tank and an alternating STA are proposed. Design Calculations: Average Design Flow = 75 GPD x 2 people/bedroom x 3 Bedrooms + 2 Bedrooms (future ADU) = 750 GPD LTAR = 0.6 GPD/SF 750 GPD / 0.6 GPD/SF x 1.0 (gravity trenches) = 1250 SF (no reduction for chambers) MIN. 50% total required infiltrative area in each STA = MIN. 625 SF An average daily wastewater flow of 750 GPD will be used. The system installation will include a new 1000-gallon, two-compartment concrete septic tank with an effluent filter on the outlet tee to serve the future ADU. The existing 1000-gallon, 2-compartment septic tank serving the 3-bedroom house will continue to be utilized. This septic tank already has an effluent filter installed on the outlet tee. An existing sewer line has been installed from the approximate area of the STA to the existing septic tank. A Bull Run Valve will be installed after the existing 1000-gallon septic tank. The existing STA consists of approximately 675 square feet of infiltrative area in a chamber trench configuration. We believe there are three rows of 12 ‘Standard’ Infiltrator® chambers. Each ‘Stan dard’ chamber measures 3’ x 6.25’, or 18.75 square feet per chamber. Effluent is distributed by a distribution box. The distribution box must be uncovered and checked during construction of the new STA. Flow equalizers, or similar product, must be installed to assure equal distribution to each trench. The distribution box must be brought to grade for future access. A new distribution must be installed to serve the new STA. Flow equalizers, or similar product, must be installed to assure equal distribution to each trench. The distribution box must be brought to grade for Page 4 future access. The new STA will consist of three rows of 19 ‘Quick 4’ Infiltrator® chambers, for a total area of 684 square feet of infiltrative area. The infiltrative area must be installed just below the topsoil horizon, but may not exceed 4-feet below native grade. Trenches must be separated by at least 6-feet of undisturbed soil. Inspection ports must be installed at both the beginning and end of each trench. Inspection ports may be cut to grade and covered with a sprinkler box for access. The property owner or occupant is responsible for keeping records on the frequency of alternating each STA. We recommend rotating the valve on an annual basis. Records must be available for review by Garfield County, if requested. We have provided a document to assist in record keeping (enclosed). The component manufacturers are typical of applications used by contractors and engineers in this area. Alternatives may be considered or recommended by contacting our office. Construction must be according to Garfield County On-Site Wastewater Treatment System Regulations, the OWTS Permit provided by Garfield County Building Department, and this design. REVEGETATION REQUIREMENTS An adequate layer of good quality topsoil capable of supporting revegetation shall be placed over the entire disturbed area of the OWTS installation. A mixture of native grass seed that has good soil stabilizing characteristics (but without taproots), provides a maximum transpiration rate, and competes well with successional species. No trees or shrubs, or any vegetation requiring regular irritation shall be placed over the STA. Until vegetation is reestablished, erosion and sediment control measures shall be implemented and maintained on site. The owner of the OWTS shall be responsible for maintaining proper vegetation cover. OPERATION INFORMATION AND MAINTENANCE The property owner shall be responsible for the operation and maintenance of each OWTS servicing the property. The property owner is responsible for maintaining service contracts for manufactured units, alternating STAs, and any other components needing maintenance. Geo-fabrics or plastics should not be used over the absorption area. No heavy equipment, machinery, or materials should be placed on backfilled STAs. Livestock should not graze on the STA. Plumbing fixtures should be checked to ensure that no additional water is being discharged to OWTS. For example, a running toilet or leaky faucet can discharge hundreds of gallons of water a day and harm a STA. If an effluent filter or screen has been installed in the OWTS, we recommend this filter or screen be cleaned annually, or as needed. If the OWTS consists of a pressurized pump system, we recommend the laterals be flushed annually, or as needed. The homeowner should pump the septic tank every two years, or as needed gauged by measurement of solids in the tank. Garbage disposal use should be minimized, and non-biodegradable materials should not be placed into the OWTS. Grease should not be placed in household drains. Loading from a water softener should not be discharged into the OWTS. No hazardous wastes should be directed into the OWTS. Mechanical room drains should not discharge into the OWTS. The OWTS is engineered for domestic waste only. Page 5 ADDITIONAL CONSTRUCTION NOTES If design includes a pump, weep holes must be installed to allow pump lines to drain to minimize risk of freezing. The pump shall have an audible and visual alarm notification in the event of excessively high water conditions and shall be connected to a control breaker separate from the high water alarm breaker and from any other control system circuits. The pump system shall have a switch so the pump can be manually operated. Excavation equipment must not drive in excavation of the STA due to the potential to compact soil. Extensions should be placed on all septic tank components to allow access to them from existing grade. Backfill over the STA must be uniform and granular with no material greater than minus 3-inch. INSTALLATION OBSERVATIONS ALL SERVICE septic, LLC must view the OWTS during construction. The OWTS observation should be performed before backfill, after placement of OWTS components. Septic tanks, distribution devices, pumps, dosing siphons, and other plumbing, as applicable, must also be observed. ALL SERVICE septic, LLC should be notified 48 hours in advance to observe the installation. LIMITS: The design is based on information submitted. If soil conditions encountered are different from conditions described in report, ALL SERVICE septic, LLC should be notified. All OWTS construction must be according to the county regulations. Requirements not specified in this report must follow applicable county regulations. The contractor should have documented and demonstrated knowledge of the requirements and regulations of the county in which they are working. Licensing of Systems Contractors may be required by county regulation. Please call with questions. Sincerely, ALL SERVICE septic, LLC Reviewed By: Carla Ostberg, MPH, REHS • Has 5-10 times more flow area than other brands, so lasts many times longer between clean- ings, increasing homeowner satisfaction • Installs in min- utes inside new or existing tanks; extendible tee handle for easy removal • Easy to clean by simply hosing off whenever the tank needs pumping • Removes about two-thirds of sus- pended solids, on average, extending drainfield life • Corrosion-proof construction, to ensure long life • Lifetime warranty Residential Biotube® Effluent Filters Applications Our patented* 4-in. (100-mm) Biotube Effluent Filters, Biotube Jr., Biotube Insert Filters, and Biotube Base Inlet Filters are ideal for residential septic tanks and have a lifetime warranty. They prevent large solids from leaving the tank, dramatically improving wastewater quality and extending the life of residential drainfields. Standard Features & Benefits • Alarm available, to signal the need for cleaning • Flow modulating discharge orifices available to limit flow rate leaving tank, mitigat- ing surges and increasing retention time • Custom and commercial sizes available Effluent from the relatively clear zone of the septic tank, between the scum and sludge layers, horizontally enters the Biotube Effluent Filter. Effluent then enters the annular space between the housing and the Biotubes, utilizing the Biotubes’ entire surface for filtering. Particles larger than the Biotube’s mesh are prevented from leaving the tank. Optional Features & Benefits Biotube Filtering Process 8-in. (200-mm) Base Inlet Filter 4-in. (100-mm) Insert Filter 4-in. (100-mm) Biotube Jr. (4-in. Biotube cartridge avail- able separately as Insert Filter) Orenco’s superior effluent filters resist clogging better than all other brands. Our stan- dard, full-sized 4-in. (100-mm) Biotube Effluent Filter provides maximum long-term protection in a complete package, with housing. Our 4-in. (100-mm) Biotube Jr., at half the size of our standard model, has more filtering capacity than the full-sized filters sold by other manufacturers. For tanks with existing outlet tees, the Biotube Insert Filter is ideal. And for low-profile tanks, there’s the Base Inlet Filter. * Covered by patent numbers 5,492,635 and 4,439,323 4-in. (100-mm) Biotube Effluent Filter APS-FT-1 Rev. 3.4 © 11/10 Orenco Systems®, Inc. To Order Call your nearest Orenco Systems®, Inc. distributor. For nearest distribu- tor, call Orenco at 800-348-9843 or go to www.orenco.com and click on “Distributor Locator.” Nomenclatures Riser wall Tank wall Filter housing Extendible PVC handle Stainless steel set screws Top seal plate Air vents Biotube® filter cartridge Solid base 4-in. Biotube Effluent Filter 4-in. Biotube Jr. 4-in. Biotube Filter (standard) 4-in. Biotube Jr. (includes cartridge and housing) Distributed By: 8-in. Biotube Filter (base inlet model) 4-in. Biotube Filter Insert (cartridge only) Junior series FT J 0418 Biotube effluent filter series Filter diameter (inches) Cartridge height (inches) W = fits Type 3034 outlet tee S = fits Schedule 40 outlet tee Options: Blank = no options M = flow modulation plate installed A = float bracket attached Blank = 1/8" filtration P = 1/16" filtration Insert FT i0418 Biotube effluent filter series Filter diameter (inches) Cartridge height (inches) W = fits Type 3034 outlet tee S = fits Schedule 40 outlet tee - For customized options (e.g., NC indicates North Carolina regions) - Blank = 1/8" filtration P = 1/16" filtration FT 04 Biotube effluent filter series Filter diameter (inches) Housing height: 36" and 44" are standard Options: Blank = no options M = flow modulation plate installed A = float bracket attached Cartridge height: 28" and 36" are standard - Blank = 1/8" filtration P = 1/16" filtration W = fits Type 3034 outlet pipe S = fits Schedule 40 outlet pipe FT 2208 14 B Biotube effluent filter series Housing height: 22" standard Cartridge height: 14" standard Options: A = float bracket FS = 2" outlet orifice FSO = 2" outlet orifice and overflow plate* Base inlet model - Blank = 1/8" filtration P = 1/16" filtration Filter diameter (inches) 08 = 8" * Also available with coupling and sleeve as a “kit”: FT-OVERFLOWKIT The Quick4® Plus Standard Chamber The Quick4 Plus Standard Chamber offers maximum strength through its two center structural columns. This chamber can be installed in a 36-inch-wide trench. Like the original line of Quick4 chambers, it offers advanced contouring capability with its Contour Swivel Connection™ which permits turns up to 15-degrees, right or left. It is also available in four-foot lengths to provide optimal installation flexibility. The Quick4 Plus All-in-One 12 Endcap, and the Quick4 Periscope are available with this chamber, providing increased flexibility in system configurations. Maximum Strength APPROVED in _____________________________________________ Quick4 Plus™ Series Quick4 Plus All-in-One 12 Endcap Benefits: • May be used at the end of chamber row for an inlet/outlet or can be installed mid-trench • Mid-trench connection feature allows construction of chamber rows with center feed, as an alternative to inletting at the ends of chamber rows • Center-feed connection allows for easy installation of serial distribution systems • Pipe connection options include sides, ends or top Quick4 Plus All-in-One Periscope Benefits: • Allows for raised invert installations • 180° directional inletting • 12” raised invert is ideal for serial applications Certified by the International Association of Plumbing and Mechanical Officials (IAPMO) Quick4 Plus Standard Chamber Specifications Size 34”W x 53”L x 12”H (864 mm x 1346 mm x 305 mm) Effective Length 48” (1219 mm) Louver Height 8” (203 mm) Storage Capacity 47 gal (178 L) Invert Height 0.6” (15 mm), 5.3” (135 mm), 8.0” (203 mm), 12.7” (323 mm) Quick4 Plus Standard Chamber Benefits: • Two center structural columns offer increased stability and superior strength • Advanced contouring connections • Latching mechanism allows for quick installation • Four-foot chamber lengths are easy to handle and install • Supports wheel loads of 16,000 lbs/axle with 12” of cover Contact Infiltrator Water Technologies’ Technical Services Department for assistance at 1-800-221-4436 4 Business Park Road P.O. Box 768 Old Saybrook, CT 06475 860-577-7000 • Fax 860-577-7001 1-800-221-4436 www.infiltratorwater.com U.S. Patents: 4,759,661; 5,017,041; 5,156,488; 5,336,017; 5,401,116; 5,401,459; 5,511,903; 5,716,163; 5,588,778; 5,839,844 Canadian Patents: 1,329,959; 2,004,564 Other patents pending. Infiltrator, Equalizer, Quick4, and SideWinder are registered trademarks of Infiltrator Water Technologies. Infiltrator is a registered trademark in France. Infiltrator Water Technologies is a registered trademark in Mexico. Contour, MicroLeaching, PolyTuff, ChamberSpacer, MultiPort, PosiLock, QuickCut, QuickPlay, SnapLock and StraightLock are trademarks of Infiltrator Water Technologies. PolyLok is a trademark of PolyLok, Inc. TUF-TITE is a registered trademark of TUF-TITE, INC. Ultra-Rib is a trademark of IPEX Inc. © 2013 Infiltrator Water Technologies, LLC. All rights reserved. Printed in U.S.A.PLUS05 0713 Quick4 Plus™ Series INFILTRATOR WATER TECHNOLOGIES STANDARD LIMITED WARRANTY (a) The structural integrity of each chamber, endcap and other accessory manufactured by Infiltrator (“Units”), when installed and operated in a leachfield of an onsite septic system in accordance with Infiltrator’s instructions, is warranted to the original purchaser (“Holder”) against defective materials and workmanship for one year from the date that the septic permit is issued for the septic system containing the Units; provided, however, that if a septic permit is not required by applicable law, the warranty period will begin upon the date that installation of the septic system commences. To exercise its warranty rights, Holder must notify Infiltrator in writing at its Corporate Headquarters in Old Saybrook, Connecticut within fifteen (15) days of the alleged defect. Infiltrator will supply replacement Units for Units determined by Infiltrator to be covered by this Limited Warranty. Infiltrator’s liability specifically excludes the cost of removal and/or installation of the Units. (b) THE LIMITED WARRANTY AND REMEDIES IN SUBPARAGRAPH (a) ARE EXCLUSIVE. THERE ARE NO OTHER WARRANTIES WITH RESPECT TO THE UNITS, INCLUDING NO IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE (c) This Limited Warranty shall be void if any part of the chamber system is manufactured by anyone other than Infiltrator. The Limited Warranty does not extend to incidental, consequential, special or indirect damages. Infiltrator shall not be liable for penalties or liquidated damages, including loss of production and profits, labor and materials, overhead costs, or other losses or expenses incurred by the Holder or any third party. Specifically excluded from Limited Warranty coverage are damage to the Units due to ordinary wear and tear, alteration, accident, misuse, abuse or neglect of the Units; the Units being subjected to vehicle traffic or other conditions which are not permitted by the installation instructions; failure to maintain the minimum ground covers set forth in the installation instructions; the placement of improper materials into the system containing the Units; failure of the Units or the septic system due to improper siting or improper sizing, excessive water usage, improper grease disposal, or improper operation; or any other event not caused by Infiltrator. This Limited Warranty shall be void if the Holder fails to comply with all of the terms set forth in this Limited Warranty. Further, in no event shall Infiltrator be responsible for any loss or damage to the Holder, the Units, or any third party resulting from installation or shipment, or from any product liability claims of Holder or any third party. For this Limited Warranty to apply, the Units must be installed in accordance with all site conditions required by state and local codes; all other applicable laws; and Infiltrator’s installation instructions. (d) No representative of Infiltrator has the authority to change or extend this Limited Warranty. No warranty applies to any party other than the original Holder. The above represents the Standard Limited Warranty offered by Infiltrator. A limited number of states and counties have different warranty requirements. Any purchaser of Units should contact Infiltrator’s Corporate Headquarters in Old Saybrook, Connecticut, prior to such purchase, to obtain a copy of the applicable warranty, and should carefully read that warranty prior to the purchase of Units. Quick4 Plus Standard Chamber ___________________________________________________________________________________ Quick4 Plus All-in-One 12 Endcap ________________________________________________________________________________ Quick4 Plus All-in-One Periscope ________________________ EFFECTIVE LENGTH48" 12" 34" QUICK4 PLUS ALL-IN-ONE PERISCOPE (360° SWIVEL) 12.7" INVERT PRESSURIZED PIPE DRILL POINTS LOCATIONS (2 PLACES) 33" 18" 8" INVERT 13" EFFECTIVE LENGTH48" 12" 34" QUICK4 PLUS ALL-IN-ONE PERISCOPE (360° SWIVEL) 12.7" INVERT PRESSURIZED PIPE DRILL POINTS LOCATIONS (2 PLACES) 33" 18" 8" INVERT 13" FRONT VIEW SIDE VIEW EFFECTIVE LENGTH48" 12" 34" QUICK4 PLUS ALL-IN-ONE PERISCOPE (360° SWIVEL) 12.7" INVERT PRESSURIZED PIPE DRILL POINTS LOCATIONS (2 PLACES) 33" 18" 8" INVERT 13" 6" 5"9"