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Home My WebLink AboutOWTS Installation Oberservations 08.31.2023U. Founded in 1971 August 31, 2023 Green Line Architects 65 North 4th Street, Suite 5 Carbondale, CO 81623 OWTS — Final Inspection Letter Observation Date: August 24, 2023 Field Rep: Ryan R. Barbone, P.E. Project Name: High Aspen Ranch, Phase 2 — 491 High Aspen Drive Project Number: GS06546.001-132 We previously provided an OWTS design for the proposed residence and garage/office building located at 491 High Aspen Drive (see Project No. GS06546.001-132, report dated November 2, 2022) in Garfield County, Colorado. As requested, we visited the subject site on August 24, 2023. The purpose of our visit was to observe components of the OWTS that were installed. At the time of our visit, we observed deviations from our design, listed in this letter. Soil Treatment Area (STA During a site visit on August 24, 2023, we observed the components of the STA were installed, but not backfilled. • Dimensions: Two 12' x 104' beds were installed with at least 6' of undisturbed soil between beds (2,496 square feet total). Four 1.5" diameter, 111' distribution laterals were installed in each bed. 104 Infiltrator@ Std. Quick4@ Chambers and 8 Infiltrator@ Quick4® Plus All -in -One endcaps were installed in each bed. • Distribution Laterals: Quick4® Chambers were installed at the time of our visit so we were unable to observe the distribution laterals and orifice size/spacing. The chambers were installed level. Observation ports were installed at the corner of each bed • Effluent Transport Lines: The automatic distributing valve (ADV) and air (vacuum) release valve were backfilled at the time of our visit. Transport lines and the manifold were exposed. Transport lines from the ADV and air vacuum release valve to the manifold obtained a minimum slope of at least 1/8-inch drop per foot. • Setbacks: Minimum setbacks to the home, tank, and property boundary were obtained. CTLIThompson, Inc. Denver, Fort Collins, Colorado Springs, Glenwood Springs, Pueblo, Summit County — Colorado Cheyenne, Wyoming and Bozeman, Montana Septic/Dose Tank and Sewer Line During our site visit, we observed a septic tank and pump tank that had been installed with interior components and had been backfilled. • Tank: A 1,500-gallon, two -compartment precast concrete septic tank and 500- gallon precast concrete pump tank were installed level and backfilled. The tanks were fitted with risers and lids. The risers on the septic and pump tanks were observed to be at least 24" inches in height to accommodate a bury depth of 24". • Pump: An Orenco PF5007 high head effluent pump and a Biotube filter were installed in the pump tank. An auto air release valve was not observed due to backfill. The STA was installed in general conformance with the plans, and the length of transport line between the air release valve and the STA manifold was close to the designed length. Power was supplied to the pumps and alarm systems. We observed alarm system functionality and a squirt test on each bed. Our observation of the squirt test indicated a squirt height of less than 1 feet from the top of the cleanout elevation in each bed. • Sewer Line: Sewer lines were in place from the residence and garage/office to the septic tank but had previously been backfilled. We were unable to verify slope and bedding. We observed multiple cleanouts along the sewer line alignments. • Setbacks: Minimum setbacks to the home, tank, and property boundary were obtained. Deviations from Design During our site visit, we observed deviations from our design: • The sewer line was backfilled prior to our arrival. We were unable to verify pipe slopes or sizes. Per a conversation with the installer, the sewer lines consist of 4- inch diameter, schedule 40 PVC pipes. • The squirt height test indicated a residual head of less than 1 foot from the observation port elevation in each bed. We were informed by the installer that the orifices drilled into the distribution laterals may have been larger than designed. Recommendations/Comments We previously provided recommendations for an Orenco Systems PF-5007 high head effluent pump based on an orifice diameter of 1/8-inch. We understand that 5/32-inch orifices were drilled. We plotted the design flow rate and total dynamic head of the installed system on the GREEN LINE ARCHITECTS Page 2 of 3 HIGH ASPEN RANCH, PHASE 2 CTLIT PROJECT NO. GS06546.001-132 pump performance curve (see attachment). The design point of the system as installed plots above the system curve for the PF5007. The PF5007 pump is insufficient to dose the system as designed and could fail prematurely. This is likely the reason we observed a squirt height test of less than 1 foot from the top of the distribution lateral cleanouts. The contractor and client have two options: 1. Discard the installed distribution laterals and reinstall new laterals with the proper orifice spacing and diameter per our previous design. 2. Remove the PF5007 and replace with a PF5050 (see attachment). We recommend flushing the distribution laterals via the cleanouts to help remove plastic debris that may have accumulated. We are available to discuss the contents of this letter. If you have any questions or need additional information, please call. CTLITHOMPSON, I ' 61683 m;a Ryan R. Barbone, P. ssi ......NG`� Division Manager, Glen rbarbone(c-)-ctlthompson.com Reviewed by: Brittany Niggeler Staff Engineer bniggeler(a)-ctlthompson.com Attachments: Pump Curve — Installed System with PF5007 Pump Curve — Installed System with PF5050 cc. snovy(a-greenlinearchtects.com mike o form44construction.corn GREEN LINE ARCHITECTS Page 3 of 3 HIGH ASPEN RANCH, PHASE 2 CTLIT PROJECT NO. GS06546.001-132 Pump Selection for a Pressurized System - Single Family Residence Project GS06546.001-132 / High Aspen Ranch Parameters Discharge Assembly Size 1.50 inches 160 Transport Length Before Valve 6 feel Transport Pipe Class 40 Transport Line Size 1.50 inches Distributing Valve Model 6402 Transport Length After Valve 110 feet Transport Pipe Class 40 140 Transport Pipe Size 1.50 inches Max Elevation Lift 5 feel Manifold Length 9 feel Manifold Pipe Class 40 Manifold Pipe Size 1.50 Inches Number of Laterals per Cell 8 120 Lateral Length 111 feet Lateral Pipe Class 40 Lateral Pipe Size 1.50 inches Odfice Size 5132 inches Orifice Spacing 4 feet 13) 100 Residual Head 5 feet lL �-- Flow Meter None inches = 'Add-on'Fdction Losses 0 feet ❑ Calculations M Minimum Flow Rate per Orifice 0.68 gpm lu 2 80 Number of Orifices per Zone 112 U Total Flow Rate per Zone 77.4 gpm E Number of Laterals per Zone 4 % Flaw Differential l st/Last Orifice 8.2 % Transport Velocity Before Valve 12.2 fps Transport Velocity After Valve 12.2 fps N 60 O l— Frictional Head Losses Loss through Discharge 17.9 feet Loss in Transport Before Valve 1,8 feel Loss through Valve 30.4 feet Loss in Transport after Valve 33.3 feet Loss in Manifold 0.8 feet Loss in Laterals 0.9 feet Less through Flowmeter 0.0 feet 'Add -on' Friction Losses 0.0 feet Pipe Volumes Vol of Transport Line Before Valve 0.6 gals Vol of Transport Line After Valve 11.6 gals Vol of Manifold 0.9 gals Vol of Laterals per Zone 46.9 gals Total Vol Before Valve 0.6 gals Total Vol After Valve 59.5 gals Minimum Pump Requirements Design Flow Rate 77.4 gpm Total Dynamic Head 95.2 feel 40 20 00 10 20 30 40 50 60 70 80 Net Discharge (gpm) PumpData PF5005 High Head Effluent Pump 50 GPM, 1f2HP 115/230V 10 60Hz, 200/230V 30 60Hz PF5007 High Head Effluent Pump 50 GPM, 314HP 230V 1060Hz, 2001230/460V 30 60Hz PF5010 High Head Effluent Pump 50 GPM, 1HP 230V 10 60Hz, 200/460V 30 60Hz PF5015 High Head Effluent Pump 50 GPM, 1-1/2HP 230V 10 60Hz, 200V 30 60Hz Legend System Curve: Pump Curve: Pump Optimal&ange: OperalirtrtQPoint: DesigMPoinl: Pump Selection for a Pressurized System - Single Family Residence Project Parameters Discharge Assembly Size 1.50 Inches 450 Transport Length Before Valve 6 feet Transport Pipe Class 40 Transport Line Size 1.50 inches Distributing Valve Model 6402 Transport Length After Valve 110 feet 400 Transport Pipe Class 40 Transport Pipe Size 1.50 inches Max Elevation Lift 5 feet Manifold Length 9 feet Manifold Pipe Class 40 350 Manifold Pipe Size 1.50 inches Number of Laterals per Cell 8 Lateral Length 1t1 feet Lateral Pipe Class 40 Lateral Pipe Size 1.50 inches Orifice Size 5/32 Inches 300 Orifice Spacing 4 feet tv Residual Head 5 feet Flow Meter None inches 2 'Add -on' Friction Losses 0 feel 250 Calculations m IU Minimum Flow Rate per Orifice 0.68 gpm 2 Number of Odfices per Zone 112 U Total Flow Rate per Zone 77.4 gpm E 200 Number of Laterals per Zone 4 C % Flow Differential lsVLast Orifice 8.2 % Transport Velocity Before Valve 12.2 fps Transport Velocity After Valve 12.2 fps to O ~ 150 Frictional Head Losses Loss through Discharge 17.9 feet Loss in Transport Before Valve 1.8 feel Loss through Valve 30.4 feet Loss In Transport after Valve 33.3 feet Loss in Manifold 0.8 feet Loss in Laterals 0.9 feet Loss through Flowmeter 0.0 feet 'Add -on' Friction Losses 0.0 feet Pipe Volumes Vol of Transport Line Before Valve 0.6 gals Vol of Transport Line After Valve 11.6 gals Vol of Manifold 0.9 gals Vol of Laterals per Zone 46.9 gals Total Vol Before Valve 0.6 gals Total Vol After Valve 59.5 gals Minimum Pump Requirements Design Flow Rate 77.4 gpm Total Dynamic Head 95.2 feet OU Orenco S Y S T E NI S 100 50 0; PumpData 10 20 30 40 50 60 70 80 Net Discharge (gpm) PF5050 High Head Effluent Pump 50 GPM, 5HP 230V 10 60Hz, 2301460V 30 60Hz Capacitor pack required for single phase pumps PF5030 High Head Effluent Pump 50 GPM, 3HP 230V 10 601-1z, 200/2301460V 30 60Hz Capacitor pack required for single phase pumps Legend System Curve: Pump Curve: Pump OptimaLQange: Operalio/point: DesigwPolnt: