Water CIPP What to Do When You re Between a Fence and a Hard Place

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1 What to Do When You re Between a Fence and a Hard Place 1, Marty S. Paris, P.E. 2, and Anthony Parker 3 1 Kimley Horn and Associates, Inc Merit Drive, Suite 1000, Dallas, TX Tel (972) ; Fax (972) connie.curtis@kimley-horn.com 2 Kimley Horn and Associates, Inc Merit Drive, Suite 1000, Dallas, TX Tel (972) ; Fax (972) marty.paris@kimley-horn.com 3 Dallas Water Utilities 2121 Main Street, Suite 300, Dallas, TX Tel (214) ; Fax (214) anthony.parker@dallascityhall.com Abstract This paper is a summary of the design and construction of DWU s first water main cured-inplace pipe (CIPP) installation. The project was located in the south Dallas neighborhood of Kessler Park and included 1,500 linear feet of 6-inch water and 6-inch wastewater in need of replacement and/or rehabilitation. Upon initial investigation, KHA found the water and wastewater mains to be located in an existing 10-foot easement along with a 6-inch gas main and overhead power lines behind the homes along the back lot lines with no alley for access. The existing easement also included multiple encroachments of fences, trees, garages, retaining walls and other structures. The preliminary design evaluated several replacement and rehabilitation alternatives, including CIPP, pipe bursting, horizontal directional drilling, open cut and alternate alignment relocations. CIPP rehabilitation of the existing wastewater line was a straightforward solution that DWU has utilized for many years, but CIPP for water mains was a new process to DWU. The design process included extensive field investigations, coordination with the lining manufacturer, preparation of technical specifications and considerations for temporary water service. This paper details several lessons learned by KHA and DWU including construction space requirements, fitting connections, service connections and testing requirements. The paper also discusses costs, the installation process, public meetings, questions from concerned citizens, construction issues, and the installation time frame.

2 INTRODUCTION As part of the 2009 Water and Wastewater Replacement and Rehabilitation Program, Dallas Water Utilities (DWU) selected Project 4209, Easement North of Plymouth, to be designed by Kimley-Horn and Associates, Inc. (KHA). This project is located in Dallas south of Interstate 30 in an affluent neighborhood known as Stevens Park Estates in the Kessler Park area of Dallas. The City of Dallas (City) had received various complaints of water quality issues due to the existing cast-iron water pipes in the area and had identified the need to replace or rehabilitate the existing 1,500 linear feet of 6-inch water and 6-inch wastewater infrastructure from Oak Cliff Boulevard to Plymouth Road (previously Kessler Boulevard). DESIGN PROCESS Identifying Constraints The first steps for the design were to gather information from the City and franchise utilities and to perform a thorough field investigation of the project limits. During the preliminary investigation and site visits, three main constructability issues began to cause concern Access, Utility Clearances, and Working Area. Photo 1 Stevens Park Estates Plat The first issue involved access to the existing infrastructure. The Steven Park Estates neighborhood dates back to the 1920 s, and the original plat created a 10-foot easement behind the homes to be utilized for both public utilities and as a common area for the neighbors to have access to the dedicated play parks which are shown on the plat as cul-de-sac type spaces behind the homes (see Photo 1). With the exception of a 10 foot sidewalk mid-way between Colorado Boulevard and Oak Cliff Boulevard (shown in Photo 4), there are no alleys, dedicated access easements, or other official or unofficial access points from this easement and common area to the surrounding streets. Over time as the properties have changed hands, this common area has been neglected and ignored to various levels. Some homeowners have built structures (including

3 garages, sheds, and retaining walls) up to or within the 10 foot common area and others have fenced across the common area blocking access to the next property. If standard open cut replacement was proposed, access for construction equipment to this common area would be impossible without disturbing property of the majority of the homeowners along the project extent. Photos 2 through 6 illustrate the accessibility issues seen during the first site visit in October The blue lines indicate the existing location of the water line, the yellow lines indicate the location of the existing gas line, and the red lines indicate the location of the existing wastewater line. Photo 2 Project Alignment Looking Northeast from Oak Cliff Boulevard

4 Photo 3 Project Alignment Looking West from Plymouth Road (Kessler Boulevard) Photo 4 Sidewalk Crossing Looking Northwest from Plymouth Road (Kessler Boulevard)

5 Photo 5 Easement Looking Northeast from Play Park Northeast of Oak Cliff Boulevard Photo 6 Easement Looking Northeast from Sidewalk

6 The second issue identified was that in the 1920 s the water, wastewater, gas lines, and overhead power were all placed within the above noted 10-foot utility easement and common area (illustrated in Photos 2 through 6 above). For open cut construction, this configuration would be very difficult to replace the water and wastewater infrastructure without disturbing the gas and overhead electric lines. It should also be noted that the Texas Commission on Environmental Quality (TCEQ) requires that all new water and wastewater lines must be no closer than nine feet in any direction unless pressure pipe is installed and then 4 feet outside diameter to outside diameter clearance is allowed. It could be possible to install a pressure rated wastewater pipe and achieve this necessary clearance, but the achievable clearance would depend on the spacing of the gas from the edge of the 10-foot easement which varies throughout the project extents. If open cut replacement was proposed, it became apparent that in order to have a level of comfort that the necessary clearances were maintained, the City would need to acquire further easement behind the homes or move the water line into the streets fronting the homes. The final issue included the necessary working space for construction behind the homes. The City would need to obtain Temporary Construction Easements from every property owner in order to access and work on the existing lines behind their homes. This easement acquisition process could take years. The City also was concerned with the amount of private property that would be disturbed during construction and the expense of returning the properties to preconstruction conditions. Over 2,000 feet of various heights of wood or steel tube fence would need to be removed and replaced, landscaping, shrubs, and trees would need to be replaced, and a few swimming pools could also potentially be negatively impacted by construction. Overall, the level of inconvenience and disturbance to the residents would be much higher than is typical to the City. Proposed Solutions After identifying the above constraints on the project, KHA and the City began discussing possible solutions. The following is a list of various solutions the City considered for rehabilitating or replacing the water and wastewater infrastructure: 1. Open Cut Replacement of the Water and Wastewater This option would require the acquisition of further permanent easement and temporary easement along the back portion of the properties. 2. Relocation of the Water Infrastructure to the Adjacent Street and Rehabilitate the Wastewater in Place This option would require the installation of a new water line in Mayflower Drive and Plymouth Road and would also require that the homeowners pay to have their water services rerouted to the front of their homes and connected to the proposed water line. However, this option would minimize the disturbance of personal property behind the homes. 3. Water and Wastewater Rehabilitation This option would require minimal disturbance to the personal property behind the homes, but would require further coordination with the water cured in place lining manufacturer to understand their product as well as the City holding special public meetings to educate the residents on the new technology being utilized on the project.

7 Other ideas were considered including pipe bursting and horizontal directional drilling, but were not found to be feasible options for installation due to the constraints identified above. It was a straightforward decision to rehabilitate the existing 6-inch wastewater line using cured in place pipe (CIPP), but the water line required further consideration. After some debate, the City decided to further investigate the third option to rehabilitate both the water and the wastewater infrastructure. Water Cured In Place Pipe (CIPP) KHA and the City proceeded to coordinate with a water CIPP lining manufacturer, Insituform Technologies, Inc. (Insituform), to understand the installation process, the level of disturbance required, and the feasibility of utilizing the technology for this project. After discussion with Insituform, the following items were identified as issues that needed further consideration: Pipe Size The existing water line was 6-inch cast iron. Insituform s equipment is generally limited to a 6-inch minimum pipe diameter with a preference of minimum 8-inch diameter. Insituform reassured the City that their product and equipment would work appropriately for the 6-inch rehabilitation, but it might be a little more difficult to maneuver some of the equipment and could require some spot replacements of some of the service connections. Fittings and Valves The CIPP cannot be installed through existing fittings (tees, crosses, bends) and valves and therefore the fittings and valves must be removed prior to installation. Since the water line was constructed by a private developer in the 1920 s, the City has no record drawings for the water line and therefore identifying the location of any unknown fittings or buried valves could only be done once the line was drained and T.V. inspection was performed. This was an issue because every fitting and valve required a pit and therefore disturbance to the homeowner s backyard and potentially fences, retaining walls, and foundations of structures. Temporary Water When installing CIPP water, the existing water line must be drained, cleaned, and lined with the new liner. This requires that the adjacent residences be placed on temporary water for the duration of the project. With so many unknowns on the project, the project schedule could have been anywhere from one month on temporary water to six months. Even with a few of the unknowns stated above, the City decided to move forward with the water CIPP option. The City and KHA coordinated with Insituform to obtain a specification for the installation and material. After review of the provided specification and a few revisions required by the City, the specification was finalized. Once the final decision was made to proceed with utilizing water CIPP for water design, KHA finalized the plans for the project, the project was bid by the City, and the project moved into the construction phase of the project. Per the bid summaries provided by the City, the bids per linear foot of 6 Water Rehabilitation by CIPP ranged from $138 to $213, with an average of approximately $170 per linear foot.

8 CONSTRUCTION PHASE Public Meetings and Residents Concerns Upon communication from the contractor that they were ready to proceed with the construction of the Kessler Park water and wastewater project, the City required that a public meeting be held so that all of the impacted residents could learn about the project, understand the level of disturbance required along the alignment, and ask any questions of the City, the engineer of record, the contractor, or the lining manufacturer. A meeting was held in July 2011 with the Steven s Park Home Owner s Association to discuss the project. After presenting the project constraints and the proposed solution, and then further discussing the technology proposed to be used, the temporary water required during construction, and the pits that would be required in homeowner s backyards to access the water services, the homeowners were given the opportunity to express concerns in the meeting and with follow up s or phone calls. The following four items were the major concerns expressed from property owners: Property Damage A few of the homeowners that owned property where the bends or valves were located were concerned about the size of the pits necessary for installation of the pipe and wanted to know the duration the pits would be open and the amount of private property that would be damaged due to the equipment required to excavate the pit. Overall, the property owners were willing to work with the City and were reasonable with the level of disturbance required for the infrastructure improvements. Safety Safety during construction was a concern of a few of the homeowners. Specifically the concern that while on temporary water there would be a 3 foot by 3 foot open hole in the back portion of their yard where their water service would be exposed. The majority of the homeowners had no issue allowing this small pit to stay open during the duration of the project, but a few homeowners with dogs and small children required that the contractor backfill the pit after the temporary water service was hooked up. Right of Entry During the survey phase of the project, the City obtained rights of entry to the properties and did so again for the contractor during construction. There were a few homeowners who resisted allowing the contractors full access to their yards during construction and one who refused access altogether. This homeowner s concern actually caused some delay during construction. Over months of issues and negotiations, the City was finally able to access the homeowner s backyard to move forward with work needed to be performed. Leeching of Chemicals During the public meeting, one of the items discussed was how the liner cures in place. The manufacturer stated that the liner is an epoxy product that will cure for five hours to a specified hardness, but, as all epoxy products do, will also continue to cure for the lifetime of the product. This caused concern for some homeowners that the liner would leech chemicals into the water that otherwise wouldn t be present if the City were to install PVC, ductile iron, or other long time industry accepted materials. The City expressed that the national standard for water material safety is for the product to be NSF61 (National Sanitary Foundation) certified. KHA

9 further researched the NSF certification and contacted several pipe manufacturers to set a standard for levels of leeching by other materials with which to compare to the CIPP water liner and hopefully appease the homeowner. KHA found that other than saying their product is NSF certified, no other manufacturer will discuss the details of the certification stating that the information is proprietary. After many conversations with the concerned homeowners, the City was able to ease their concerns and assure the homeowners that by being NSF61 certified, the product was safe for installation. Construction Process Since this project was the first water CIPP project to be installed within the City of Dallas, the inspector and project manager within the City monitored the process closely. The following is a summary of the steps required for installation of water CIPP: 1. Temporary Water All water services must be transferred over to a temporary water line. 2. Isolation of the System The existing water line must be isolated from the overall City water system until final approval of construction. 3. Drain the Existing Line The existing line must be empty and dry for the installation of the CIPP. 4. Remove Existing Corporation Stops The majority of the water services connect via a corporation stop inserted into the water main. These corporation stops must be removed and replaced as is standard with new water mains, but also because the corporation stop protrudes too far into the water main and will negatively impact the installation of the liner if allowed to remain. 5. Install New Corporation Stops New corporation stops are ground down to the appropriate length (as specified by the liner manufacturer) and installed back in the existing tap location. 6. TV Inspection TV inspection of the line is required to identify the level of cleaning required for the water line and to identify any necessary areas that are not structurally acceptable and would need to be replaced by open cut methods. 7. Clean the Existing Line Cleaning of the line must be performed in accordance with AWWA M Remove All Valves and Fittings All valves and fittings (including tees, crosses, and bends) must be removed prior to the installation of the CIPP. 9. TV Inspection The existing water line must be TV inspected again after the line has been cleaned and the valves and fittings are removed to confirm that the line has been cleaned to AWWA M28 standards. 10. Dig Pits for CIPP Shots Pits must be dug at either end of the shooting limits. Requires a space of approximately 10 foot by 5 foot for each pit. Typically, the limits of each shot will be from one fitting location to another fitting location. The length of material to be installed with each shot is established by the liner manufacturer and the pit locations required should be established prior to the ordering of the material. 11. Install and Cure CIPP Assume that there will be one shot of CIPP done per day including 5 hours for curing. Lengths of each shot will vary depending on pit locations and accessibility of the launch site. 12. Pressure Test Liner manufacturer tests the pressure of the installed liner after it has been cured, but before any water service connections are made.

10 13. Open Water Services The liner manufacturer has a robot that moves through the installed pipe and cuts holes where the service corporation stops are located. The robot connects to each corporation stop with a proprietary T-Bolt that threads backwards into the corporation stop creating a seal inside the water line. 14. TV Inspect and Clean the Line Per the DWU Specification, the water line is required to be TV Inspected and cleaned again and the TV Inspection must be approved by the Inspector. 15. Prep for Connection At every end of CIPP, a special coating is required prior to attaching any fitting. This coating is provided by the liner manufacturer and is applied after approval that the line is clean 16. Install Hymax Fittings In order for the CIPP to connect to any bend, valve, or other existing water line, a Hymax fitting must be installed. This fitting will connect a piece of PVC to the end of the CIPP pipe and then the PVC can be connected to the bend, valve, tee, cross, or other pipe material. 17. Load the Line At this point, the Contractor is prepping for a hydrostatic test. The water line must be loaded to test for pressure, however, the line cannot be connected to the existing system. A constant source of water, like a tap to an adjacent line, must be located to load the line. 18. Contractor Pre-Test The liner manufacturer will run the same hydrostatic test as the City and make sure they pass prior to calling out the City to do the same. For the City of Dallas, the test performed is to hold 150 psi for 2 hours. 19. City Hydrostatic Test Once the contractor and liner manufacturer believe they can pass the City test, the City Inspector will run the test on the line to hold the required 150 psi for 2 hours. 20. Chlorination Upon passing the hydrostatic test, the City will chlorinate the line and the contractor must run a 24 hour flush of the water line. 21. Water Samples After Chlorination, water samples are taken by the City twice. Once the samples pass the first test, a second sample will be taken and tested again. 22. Connect Water Services After passing the chlorination and water samples test, the water services can be connected from the corporation stop to water meter and the service line can be taken off temporary water and connected to the rehabilitated water line. 23. Tie Into Existing System The rehabilitated water line is now no longer required to be isolated from the rest of the City system and any isolation valves that had been closed can now be opened and the water main placed in service.

11 Project Schedule and Construction Issues As with many construction projects, this project ran into a few unforeseen issues during construction. In July 2011, when the City first approached the homeowners, the City anticipated that the homeowners would need to be on temporary water for no more than two months meaning that all of the above steps could be achieved in that timeframe. The actual project schedule was delayed such that the homeowners were placed on temporary water on January 27, 2012 and were tied back into the City system on October 4, 2012, or just over nine months. Obviously there were issues that delayed the construction. The following is a brief summary of the schedule and the issues which caused the delays: January 27 th Connect Temporary Water February Contractor and Insituform are not in agreement on who is responsible for digging pits, removing fittings, etc., requiring City involvement. This contributes to delaying the project through March. April How will the system be isolated? City realizes there are insufficient isolation valves on the City lines and is required to install new valves in order to not remove entire neighborhood from service. This contributes to delaying the project through May. June Contractor is installing new corporation stops, but one homeowner will not allow the contractor to dig necessary pit to replace the corporation stops. Claims water line is outside the existing easement lines and is encroaching on his property. This contributes to delaying the project through June. July How will the fittings be removed in the homeowners backyards? Contractor requires City to assist in coordination of pit locations and right of entry. This contributes to delaying the project through July and into August. August 19 th Insituform flies in crew and is on the ground installing water CIPP. Crew is flown out in between shots to finish a previous job somewhere else in the country and must delay a few days. CIPP installation not finished until September 4 th. September 19 th Water line fails hydrostatic test. Insituform must schedule to fly crew back in to tighten service connections and contractor must tighten Hymax fittings. This contributes to delaying the project another week. October 1 st through 4 th Reconnect homeowners to City water main. Remove temporary water. Overall, the homeowners had no issues with being on temporary water for the duration of the project, and were mostly unaware of the delays noted above. The City was able to navigate the issues as they came up and provide the residents a new water line with minimal disturbance to their property.

12 LESSONS LEARNED The City and KHA learned quite a bit on this project. It s inevitable that you can look back on a project and know you could have prevented an issue if you just would have thought of this or known that. The following is a breakdown of things as an Engineer, a City, or a City Inspector that someone should probably know or think about when designing, constructing, or managing the installation of water CIPP. Engineers The following items are lessons that KHA learned while designing and assisting with RFI s during construction that we thought would be good lessons for any engineer designing a water CIPP project. Understand the Product and Installation This is fairly straight forward, but cannot be emphasized enough. If you don t understand how the product is to be installed, you cannot properly design the project. Contact the liner manufacturer early in the project and have them involved with writing specifications and placing appropriate direction to the Contractor on the plans. For instance, we did not place a note regarding the use of Hymax fittings on the plans at the connections to fittings and valves. This lack of clarity caused some confusion for the contractor and inspector during construction. In the future, we will be sure to note the use of Hymax fittings so that it is clear during bidding that the contractor will have to know how to properly install this specialized fitting. Construction Area and Pit Locations Like with wastewater CIPP, the water CIPP liner is trucked in and there must be a staging area to shoot the liner from. Unlike wastewater CIPP, there usually isn t a manhole with which to begin and end a shot of liner and therefore pits must be dug and the identified limits of a liner shot must be identified prior to the ordering of the material for construction. Prior to proposing the use of water CIPP, the engineer should think through where this construction area will need to be, how many of these areas would be required because the equipment may need to move for various shots, and if a contractor can easily access an area to dig a pit for installation. Noting the pit locations and construction area on the plans is not required since that is a means and method of the contractor, but thinking through how a contractor would set it up is necessary to make sure it is feasible. Isolation of System During the construction, the entire area to be rehabilitated has to remain isolated from the rest of the City water system. During the design phase, the Engineer should consider if this is possible or if additional isolation valves would be required. During the construction of the Kessler Park project, it was realized that in order to isolate the necessary one block of water line for the project, the City would also have to isolate a large portion (around 4 blocks) of the rest of the neighborhood. A quick design was required from KHA to install isolation valves at the necessary locations so as not to negatively impact the entire neighborhood during construction.

13 City Engineers or City Staff The following items are lessons that the DWU Project Manager learned while managing the design and construction of the project and are items he would recommend other cities consider prior to design and construction of a water CIPP project. Understand the Product and Installation This item is consistent with the lesson learned above from the Engineer. If the City staff does not understand what the product is and how the product is to be installed, they cannot properly comment on the design or manage the construction of the project. The City should be part of the Engineer s correspondence with the liner manufacturer and have them involved with writing specifications and placing appropriate direction to the Contractor on the plans. Public Meetings - Having the public meeting with the HOA for the Kessler Park project was a big factor in the homeowners being comfortable with what was being done behind their homes. However, the City would recommend that all parties speaking at the meeting (City Project Manager, contractor, liner manufacturer, engineer, etc.) meet prior to the meeting to discuss exactly what each person will say, anticipate potential questions and how they would be answered, and, in general, make sure everyone is prepared to present a uniform and organized project to the citizens that will attend. On the Kessler Park project, a few of the issues and homeowner concerns stemmed from things the contractor and liner manufacturer said in the meeting. If we all had met prior to the public meeting, a few of those concerns could have been avoided. Pre-Construction Meeting After the bid is awarded, it is in the City s best interest to have a pre-construction meeting and discuss the project in detail to make sure the contractor and the liner manufacturer understand who is going to be responsible for what during construction. Since the Kessler Park project was part of a larger construction contract including many other projects, a pre-construction meeting specifically for this project was not held. A few months after the homeowners were moved over to temporary water, it became obvious to the City that the contractor and liner manufacturer had barely discussed the installation of the project. The City called a meeting and the contractor was under the impression that the liner manufacturer was managing the entire installation of the water line including digging pits, replacing fittings, reconnecting service, etc. The liner manufacturer contended that all they were contracted to do was install the water CIPP and reconnect the internal water service connections. This was an issue that could have easily been remedied if a pre-construction meeting on this specific project had been held. Isolation of System During the construction, the entire area to be rehabilitated has to remain isolated from the rest of the City water system. During the design phase, the City needs to review how the section of their system will be isolated without impacting other portions of their system. During the construction of the Kessler Park project, it was realized that in order to isolate the necessary one block of water line for the project, the City would also have to isolate a large portion (around 4 blocks) of the rest of the neighborhood. A quick design was required from KHA to install isolation valves at the necessary locations so as not to negatively impact the entire neighborhood during construction.

14 City Inspectors The following items are lessons that the DWU Inspector learned while managing the construction of the project and are items he would recommend other Inspectors to consider prior to managing the construction of a water CIPP project. Understand the Product and Installation This item is consistent with the lesson learned above from the Engineer and City Staff. If the Inspector does not understand how the product is to be installed, they cannot properly manage the construction of the project. The Inspector should attend the pre-construction meeting and make sure the liner manufacturer walks them through the installation process and gives the Inspector time to understand how the process works and ask any questions there that do not make sense or need clarification. Product Samples Because this product is proprietary to the liner manufacturer, there is no way for an Inspector in the field to confirm that what the liner manufacturer is installing is the correct product. The Inspector has to take the liner manufacturer s word that what is being installed is what was specified in the project specifications. Based on the Kessler Park project, it would be recommended that the liner manufacturer be required to provide the Inspector samples of the products to be installed so that during construction the Inspector has something to make sure the appropriate materials are being installed. The following items are recommended to be provided: o Section of cured liner This section should match the thickness of the liner that will be installed on the project and can be used by the Inspector on the project site to confirm that the appropriate material was installed. o T-bolts The T-Bolts with washers are used to connect to the corporation stops on the water services. Providing a sample of T-bolts and washers that are planned to be used on the project can be used by the Inspector on the project site to confirm that the appropriate material was installed. Hymax Fittings The Hymax fittings are specialized fittings used to connect the water CIPP to PVC which then can be connected to valves, bends, tees, etc. It is important that the Inspector know the appropriate installation process and torque required for the proper installation of these fittings. For the Kessler Park project, the project failed hydrostatic testing multiple times. Part of the issue was loose service connections which the liner manufacturer had to fix, but the main issue came at the Hymax fittings which were not tightened properly. Once the Hymax fittings and the service connections were tightened, the water line had no issues passing the remaining testing. CONCLUSIONS The Kessler Park water line rehabilitation project utilized water cured in place pipe (CIPP) for the first time within the City of Dallas. The project was challenging and had many issues that required quick and creative thinking to provide effective solutions. The lessons learned on the Kessler Park project should help Dallas Water Utilities be well prepared for utilizing water CIPP as a feasible solution if they once again find themselves stuck between a fence and a hard place.

15 REFERENCES Bid Tabulations webpage. City of Dallas, Texas ftp://ftp.dallascityhall.com/bid%20tabs/ Canyon, Don. Personal Interview. City of Dallas, Texas. 15 January 2013 Chapter Design Criteria for Domestic Wastewater Systems. Texas Administrative Code. 21 January Manual of Water Supply Practices M28 Rehabilitation of Water Mains. 2nd ed. Denver, CO: American Water Works Association, Print. Parker, Anthony. Personal Interview. City of Dallas, Texas. 15 January 2013