February 2018 Vol. 73 No. 2


CUIRE to Evaluate Potential Release of Organic Chemicals During Trenchless CIPP Pipe Rehab

Sewer rehabilitation using cured-in-place pipe (CIPP) trenchless technology has become an increasingly common method to preserve underground infrastructures due to its feasibility, cost-effectiveness and reduced social impacts. Since it was introduced in 1971 as an alternative to digging up and replacing sewers, hundreds of millions of feet of rehabilitated pipe have been installed around the world.

In response to this growing use and recent industry reports, NASSCO submitted requests for proposals to facilitate a formal review of potential health impacts associated with CIPP. Of particular interest is the use of polyester resins in CIPP that result in volatilization of styrene during the curing process. Previous studies have focused on the concentration of styrene present in the air of residential homes tied to sanitary sewers during pipeline renewal. Very few studies, however, looked into the impact that styrene has on the safety and health of construction workers and the general public, when used for rehabilitating  sanitary and storm sewer pipes.

Therefore, NASSCO saw a critical need to study organic chemical emissions (both in gas and liquid-phase) associated with the CIPP installation process, and recommend methods to mitigate any potential adverse impacts on human health.  After careful consideration of all responses received, NASSCO awarded the review to the Center for Underground Infrastructure Research and Education (CUIRE) at the University of Texas at Arlington.

The overall goal of this two-phase project is to evaluate the potential release of organic compounds during pipe rehabilitation using the steam cure CIPP method. Phase I, which CUIRE began in December 2017 and expects to complete early April 2018, consists of the following:

Task A: Review recent publication(s) that propose the presence of organic chemicals and other available literature relating to emissions associated with the CIPP installation process.

Task B: Develop a scope of services for additional sampling and analysis of emissions during the field installation of CIPP using the steam cure process.


In conducting Task A, CUIRE researchers will develop a work plan and schedule to verify findings from the literature review, as well as gain additional data where insufficient data is found. The work plan will cover emissions from steam-cure CIPP installation sites, and will be peer-reviewed by qualified professional environmental consultants.

The data collection and analysis work plan will evaluate, in addition to styrene, other volatile organic compounds (VOCs) or contaminants of concern generated during the curing process. Data collection will quantify VOCs to determine if there is an exposure concern, and will estimate styrene emission per pound of resin cured.

Sampling and analysis of styrene and other VOC concentrations within the CIPP work area will use an approved method for VOCs or gaseous organics, such as Environmental Protection Agency (EPA) Method TO-17 Determination of Volatile Organic Compounds in Ambient Air Using Active Sampling Onto Sorbent Tubes, ASTM-D5466 15 Standard Test Method for Determination of Volatile Organic Compounds (VOCs) in Atmospheres (Canister Sampling Methodology), or OSHA 09 Sampling and Analytical Method for Styrene. Personnel sampling will use personal exposure monitors for parts per million (PPM) level for VOCs over an eight-hour shift.

The measured air concentrations will be compared values from Texas Commission on Environmental Quality (TCEQ) Texas Air Monitoring Information System (TAMIS) database, which contains short-term and long-term effect screening levels and air monitoring comparison values for thousands of air pollutants, including VOCs and hazardous air pollutants (HAPs). Measured concentrations will also be compared to other appropriate values from agencies such as OSHA, ACGIH and NIOSH. Organics in condensate will be evaluated, as well as in simulated rainfall runoff.

The plan for Task B will include:

Measurement of styrene and other VOC concentrations within the CIPP work area

Collection of appropriate control/background samples

Emissions analysis including the steam exhaust and other sources such as emission from the termination manhole

Condensate analysis

Area air samples

Project Team

Mo Najafi, Ph.D., will supervise this project and identifies sources of information related to emissions from the CIPP process for Task A. He will also provide expertise in field installation of CIPP using the steam cure process for development of the sampling plan (Task B).

Najafi, professor and director of CUIRE, is also founder and editor-in-chief of the ASCE Journal of Pipeline Systems, and author of four books on trenchless technology published by McGraw-Hill: Pipeline Renewal and Asset Management; Trenchless Technology Planning, Equipment, and Methods; Trenchless Technology Piping: Installation and Inspection; and Trenchless Technology: Pipeline and Utility Design, Construction and Renewal.

Dr. Melanie Sattler, Ph.D., will provide quality control for the literature review of Task A and prepare the Task B plan for sampling and analysis of emissions. She serves as the Syed Qasim Endowed professor of Environmental Engineering at UTA with a specialization in air quality.

Kevin Schug, Ph.D., will develop a plan for emissions analysis of Task B. He serves as the Shimadzu Distinguished professor of Analytical Chemistry, and founder and director of the Collaborative Laboratories for Environmental Analysis and Remediation (CLEAR) at UTA. His research group solves problems using state-of-the-art sample preparation, gas chromatography, liquid chromatography, spectroscopy and mass spectrometry techniques.

Graduate research assistants at CUIRE will assist in conducting the literature review for Task A.

The Institute for Underground Infrastructure (IKT) will access German and European publications to augment the literature review of Task A. A neutral, independent non-profit institute in Gelsenkirchen, Germany, IKT works on solving practical and operational issues concerning underground sewers, pipes and other conduit engineering. The institute conducts research projects, material testing, CIPP liner testing, consultations and seminars on the construction, operation and renovation of underground infrastructures. The IKT Test Centre is a supervisory body for CIPP liners and is recognized by the German Institute for Construction Technology (DIBT). It is accredited to European Standards for selected mechanical and technical tests on CIPP liner systems. Specific team members include:

Bert Bosseler, scientific director of IKT and honorary professor at the Institute for Geotechnical Engineering (IGTH), Hanover University, and a lecturer for sewer and pipeline engineering at the universities in Bochum, Weimar and Munich.

Thomas Brueggemann is a project manager of ecological evaluation of liner systems with the German Environmental Protection Agency.

Dieter Homann is director of Material Testing at IKT and a member of the DIBT Wastewater Sewers committee. He is an expert for CIPP liners and regularly publishes the report on results of IKT CIPP liner tests.

(817) 272-9177, cuire.org

(410) 442-7473, nassco.org

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