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HomeMy WebLinkAboutFile Documents.800 E Hopkins Ave.0057.2018 (3).ARBK 130 MINERS DRIVE • LAFAYETTE, COLORADO 80026-2951 • 303-666-8112 • FAX: 303-666-4169 www.ponderosa-assoc.com October 12, 2016 Mr. Shaun Donnellan Larkspur Condominium Association 402 Widget Street Basalt CO 81621 Transmitted via e-mail: skdonnellan@gmail.com, Re: Larkspur Condominium Drain Assessment Our File N o.: 161016 Mr. Shaun Donnellan, Pursuant to your request, Ponderosa Associates has evaluated the conditions reported as deteriorating sewer piping at the Larkspur Condominiums located at 800 East Hopkins Avenue, Aspen, CO 81611. Purpose: The purpose of this report is to detail our findings regarding the conditions observed in the sanitary sewer drain piping and provide recommendations for future use and maintenance at the Larkspur Condominiums. Procedure: I inspected and photographed claim related conditions on October 5, 2016. At the time of my inspection, I met with Mr. Rob Lipton (Alpine Valley Services) and for portions of the inspection with Ms. Carol Crocker (LCA) was present. Mr. Lipton had coordinated the assistance of two plumbers to provide drain line scoping/videoing. I worked with and directed the plumbers (Jesse & Jeremy), observing conditions of the existing piping between the upper and lower units and the horizontal underslab piping that delivers waste to the lift station at the west end of the building. ROBERT J. CALDWELL, P.E. JOSEPH H. ROMIG, PH.D. SETH W. BAYER, P.E. THOMAS FEIEREISEN, MSME, P.E. MICHAEL J. MCCORT, MSCE, P.E. MARK T. BURNS, P.E., C.F.E.I. ROBERT S. HOIT, BSCM JAMIE M. LAROCQUE, BSCE JODIE E. IMMELL, BSME MATTHEW S. PITMAN, P.E. SEAN R. CALDWELL, P.E. COLIN M. WEIN, BSME TEGAN SMITH, BFA LUCAS W. BARNES 04/06/2018 Mr. Shaun Donnellan - Larkspur Condominium Association October 12, 2016 Page 2 of 8 130 MINERS DRIVE • LAFAYETTE, COLORADO 80026-2951 • 303-666-8112 • FAX: 303-666-4169 www.ponderosa-assoc.com Background: The building is a precast concrete condominium building with five lower and five upper two story individually owned condominiums. The lower condominium spaces are labeled A1 through A5, the upper level condos are labeled B1-5. The units are numbered beginning with 1 at the west continuing through 5 at the east end. For reference, the following aerial photo with labels is provided: Figure 1: Aerial photo of the property. According to the Pitkin County Assessor’s information the building was built in 1974. The sanitary sewer drains were constructed with cast iron piping and have recently been associated with clogging & flooding incidents. 04/06/2018 Mr. Shaun Donnellan - Larkspur Condominium Association October 12, 2016 Page 3 of 8 130 MINERS DRIVE • LAFAYETTE, COLORADO 80026-2951 • 303-666-8112 • FAX: 303-666-4169 www.ponderosa-assoc.com Findings and Discussion: The intent of this inspection was to assess via visual observation the conditions of the vertical drain pipes (stacks) for observed deterioration, and if possible collect a sample section of piping for further lab analysis. An inspection was scheduled for 9am Wednesday October 5, 2016, due to travel delays I was not able to make it to the site until about 10:30am, at which time we proceeded. The videoing of the drain lines was able to be observed live, however, the plumber’s equipment was not able to record video for later use. Where possible, I took digital photos of the live video feed for preservation. We observed/scoped sanitary drain piping in Units B1, B2, A5, B3 and A2. The plumbers removed toilets for access to the drain line, the videoing or scoping was performed and then they replaced the toilet along with wax seals and sealants. Individual Unit Sanitary Drain Piping: Within the cast iron drain pipes, I observed moderate to severe corrosion on the inside face of the pipes. The corrosion creates a significantly rough surface that no doubt can lead to backups in the drain lines depending on waste introduced to the pipe. For reference, the following photos are indicative of the corrosion we observed: Photo 1: Screen shot of scope display, while videoing from A1 Master Bath toilet drain. Note corroded texture of inner wall of pipe. 04/06/2018 Mr. Shaun Donnellan - Larkspur Condominium Association October 12, 2016 Page 4 of 8 130 MINERS DRIVE • LAFAYETTE, COLORADO 80026-2951 • 303-666-8112 • FAX: 303-666-4169 www.ponderosa-assoc.com Photo 2: Photo of video screen, with scope located approximately 1-2' in from the upper level powder room lavatory drain of A5. Large jagged deposit found on pipe wall at left. Photo 3: Photo of scope screen within A5, powder room drain. 04/06/2018 Mr. Shaun Donnellan - Larkspur Condominium Association October 12, 2016 Page 5 of 8 130 MINERS DRIVE • LAFAYETTE, COLORADO 80026-2951 • 303-666-8112 • FAX: 303-666-4169 www.ponderosa-assoc.com Photo 4: Lower level toilet drain Unit A2. (Still taken from video of live feed) The drains observed had some portions of the existing cast iron drains replaced with PVC piping. For example the following scenarios of cast iron and PVC were observed/reported: • B1 - From the master bath toilet the original cast iron was present to the powder room drains (some areas had poor slope, with ~1/4” depth of liquid held in the bottom of the line), the drains transitioned to PVC in an area perceived as the wall of the powder room below (exact location not determined) • B2 – From the master bath toilet the original cast iron was present to the powder room drains, where it transitioned to PVC (exact location not determined) • A5- all cast iron present from powder room toilet and master bathroom toilet below. • Mr. Barry Lindahl, the contractor working on A5, indicated all of the A4 drain pipe was removed and replaced with PVC as a result of a prior flood (he was involved in the restoration). • B3-The upstairs toilet drain was cast iron for a distance of about 10’ where it transitioned to PVC (likely associated with a powder room remodel below). • A2 had original master bathroom (lower level) cast iron drains into the slipformed main/collector line. 04/06/2018 Mr. Shaun Donnellan - Larkspur Condominium Association October 12, 2016 Page 6 of 8 130 MINERS DRIVE • LAFAYETTE, COLORADO 80026-2951 • 303-666-8112 • FAX: 303-666-4169 www.ponderosa-assoc.com The drain piping servicing the individual units was largely concealed within walls and floors/ceilings. The main drain plumbing for powder room toilets was encased in precast concrete walls, or, where remodels were performed the pipe was generally enclosed by high quality finishes such as mirrored walls or tiling. Behind some refrigerator locations, plumbing access holes were present, sections of cast iron drain piping were observed, however they were largely vertical sections, intermixed with water service lines. I would have liked to cut a section of piping for lab analysis, however due to the conditions found, the drain lines behind the refrigerators would not likely be the exemplary worst case scenario of deterioration and, access & subsequent repair would have been very difficult and intrusive. I decided based on the inspection observations I was able to perform, I had enough information to form my opinion, and the sample collection would not be feasible at this point. Lower Level Collector Drain From the lower level A5 toilet drain, the scope was extended into the main sanitary collector line, and extended the length of the building to the west to the lift station. The main sanitary collector line had been lined with a slipform lining, its presence was identified with the scope, for reference a screenshot of the scope screen is provided: Photo 5: Slipform lined section of pipe. Appearance of installation is good, the variations in the surface observed are likely the forming against the rough inner texture of the existing pipe wall. 04/06/2018 Mr. Shaun Donnellan - Larkspur Condominium Association October 12, 2016 Page 7 of 8 130 MINERS DRIVE • LAFAYETTE, COLORADO 80026-2951 • 303-666-8112 • FAX: 303-666-4169 www.ponderosa-assoc.com There is a slight “belly”, or sag in the main/collector pipe at approximately 60’-80’ from the A5 lower level toilet, which correlates with an area about 10’-30’ from the lift station at the east end of the building. There was some sludge buildup past this area. It is likely that depending on liquid flow through the pipe this can be washed out, however, lack of use, or intermittent use can lead to buildup and blockage as solids build up there. Summary of Findings & Recommendations In general, the pipe scoped was moderate to severely corroded on its inner surfaces. The wall thickness of the pipe is likely 3/16”+/-. Without a sample I cannot quantify the deterioration or provide a prediction as to the remaining expected performance. However if the main collector has already necessitated slipform lining, the vertical unit piping likely has areas of corrosion that could begin leaking in the near future. On the date of my inspection there was little waste buildup in the lines. However, the first toilet drain exposed, in the master bathroom of B1, had a hand wipe hooked/caught in the corrosion of the inner wall of the cast iron drain. With the reported intermittent use of the units and the potential for rental use, the consistency of the waste discarded in the toilets and drains cannot be controlled. With the condition of the drain piping and potential for materials that don’t degrade or disintegrate (as readily as toilet paper) being caught on the pipe walls, I advise replacing the cast iron piping with smoother walled PVC piping. I do realize this is not an easy or convenient undertaking. If phasing is necessary, the lower unit drain piping should be considered for replacement first, as this piping experiences the heaviest use, collecting waste from the upper units, and has appeared to have more significant corrosion. Regardless, or if replacement is not immediately feasible, action should be taken to urge tenants to not inundate the system with materials that do not readily disintegrate or deteriorate, i.e. wipes, flushable feminine products, paper towels, etc. The condition of the slipform lining on the inside of the main/collector piping below the lower level units appears to be functioning, however it was necessitated by deterioration and collapse of the existing cast iron pipe; this pipe should also be replaced eventually. The liner possibly slows deterioration, however I would not advise long term reliance on the existing piping as the form for the liner. 04/06/2018 Mr. Shaun Donnellan - Larkspur Condominium Association October 12, 2016 Page 8 of 8 130 MINERS DRIVE • LAFAYETTE, COLORADO 80026-2951 • 303-666-8112 • FAX: 303-666-4169 www.ponderosa-assoc.com Conclusions/Opinions: Based upon my training, education and experience, and my examination and analysis of subject reported existing cast iron sanitary sewer drain piping, I have reached the following conclusions: • The cast iron drain piping is nearing the end of its performance life and should be replaced. • Roughness of the inner wall of the piping is likely prone to contribute to backups when materials with fiber strengths stronger than toilet paper are discarded in the drain lines, catching on the rough inner pipe surface. o As a temporary attempt at preventing the discard of these materials signage can be placed in units to urge tenants to not discard these materials in drains. • If/when replacement of the drain lines is performed, lower units with plumbing that has serviced more drainage should be replaced first (if phasing is necessary). • The lower level main/collector drain should eventually be replaced as well, as the original piping providing the form for the slip liner will likely continue to deteriorate with time. This piping can be replaced in sections as the unit piping is replaced. The opinions and recommendations expressed in this report are based on the information available at the time of this writing. Should additional information become available in the future, the opinions and recommendations expressed in this report are subject to change. Please contact me if you have any additional questions or concerns regarding this matter. Sincerely, PONDEROSA ASSOCIATES, LTD. Mark T. Burns, P.E., C.F.E.I. October 12, 2016 04/06/2018