Purdue University researchers have just completed a three-year study of two popular methods used to repair damaged culverts and pipes called spray-on lining and cured-in-place-pipe (CIPP) lining.
Because both practices bring raw chemicals onsite, environmental contamination, fish kills, and downstream drinking water contamination has occurred. Potentially hazardous conditions can be also created near the worksite during the plastic manufacture repair process, the research shows.
Water contamination incidents associated with CIPP lining have been documented in 13 states, including Pennsylvania.
One incident in July in Pennsylvania resulted in the Department of Environmental Protection issuing a notice of violation to the Borough of Carlisle in Cumberland County saying contractors working on sewer pipe near Letort Spring Run likely resulted in a discharge of heated water mixed with a Styrene-based resin that discharged upstream from the site of the July 31 fish kill.
DEP explained in the NOV the contractors were performing a “cured-in-place pipe (CIPP) installation” in the Letort Interceptor as part of the Borough’s ongoing rehabilitation project. As part of the CIPP process, the contractor uses heated water in contact with a Styrene based resin.
The results from samples taken by DEP and listed in the NOV show evidence of Styrene.
The Fish and Boat Commission has also undertaken an investigation of this incident.
The Fish and Boat Commission has also undertaken an investigation of this incident.
The new Purdue study makes a series of recommendations for preventing air and water pollution from the CIPP process based on scientific literature reviews, a survey of 32 transportation agencies, and field-testing in California, New York and Virginia.
Multiple parts of the final report were independently peer-reviewed before the document’s release.
Findings
The report found CIPP lining practices involve the chemical manufacture of plastic liners outdoors. To accomplish this, raw materials must be brought onsite and handled. Before, during, and after each liner is manufactured, the materials are often physically cut.
These practices may provide opportunities for pollutants to be released into air, water, and soil during setup, product manufacture, cleanup, and after contractors leave the worksite.
CIPP lining associated contamination has been primarily due to the release of uncured resin, solvents, manufacturing byproducts, and wastes during and after construction.
Odor, fish kill, downstream drinking water contamination incidents, and violations of state water pollution laws have been reported.
The few field‐ and bench‐scale studies available indicated that styrene has often been the only contaminant tested for but a variety of other volatile organic compounds (VOC) as well as semi-volatile organic compounds (SVOC) can been released into water.
Levels have exceeded aquatic toxicity thresholds for freshwater indicator species and U.S. Environmental Protection Agency (EPA) drinking water health-based limits. Sometimes chemical contamination was detected for several months after outdoor CIPP manufacture.
A list of degradation products (32) for initiators used for past CIPPs (Perkadox®, Trigonox®, Butanox®, N,N-Dimethylanaline®, Norox®) was included in the study, along with a list of chemicals found in uncured resins used for CIPP, leaching from CIPP after manufacture, and chemicals extracted from CIPP specimens (that may leach).
Recommendations
Among the recommendations included in the study are--
-- The project team recommends that agencies that conduct CIPP manufacture or oversee projects take two actions simultaneously. First, it is recommended that agencies request a free health hazard evaluation from U.S. NIOSH with a set of representative CIPP projects, not every CIPP project.
-- Second, simultaneously agencies should also upgrade existing outdoor CIPP manufacture construction practices, require emission capture and require confirmation they were captured, and provide more oversight that includes well-trained environmental monitoring and industrial hygiene professionals to CIPP worksites.
-- Air monitoring should be conducted to determine if pollutants were released into the environment. The type of monitoring recommended to detect the pollutants emitted can be provided to the CIPP Contractor, Engineer, or Consultant by requesting a free National Institute for Occupational Safety and Health (NIOSH) health hazard evaluation.
-- The outdoor CIPP manufacturing process requires engineering and administrative controls as well as safety upgrades to protect the health of CIPP workers as well as transportation agency, and other workers (i.e., consultants, construction inspectors) nearby as well as the environment and public from harm. This can include (1) minimizing dermal and inhalation exposures, (2) capturing emissions and confirming this by chemical monitoring, and (3) using appropriate personal protective equipment even for site observers.
-- Water testing before and after the installation is recommended. Sampling at the pipe inlet and outlet immediately before and after the liner is placed in service should constitute temporal (and spatial) sampling events (estimated to be 4 samples).
-- Upon installation, the liner should be rinsed before return to service. Rinse water should be collected and properly disposed.
-- No water should be allowed to pass through the newly lined pipe for at least 24 hours, unless representative chemical testing data specific to that site indicates the construction activity did not release materials (i.e., cutting dust, resin, etc.) and the liner does not contain or leach compounds that exceed aquatic organism toxicity thresholds for chemicals of concern or state water quality standards.
-- A list of construction specification language for spray-on lining projects and a separate list for CIPP lining projects can be found in Sections 6 and 7 of the study (beginning on page 34).
-- Agencies who desire to determine if a CIPP lining project caused chemical water contamination should require independent water testing. At CIPP manufacturing sites, chemical contamination was found in standing water, rinse water, and storm water immediately after and 22 days after CIPP manufacture, depending on the site.
-- Because spray-on lining and CIPP lining are plastic manufacturing activities conducted outdoors, construction practices that limit chemical release and environmental monitoring should be applied.
-- State water quality discharge limits should be considered where the lining practice may be used.
-- Another challenge with environmental monitoring is that little information exists regarding the chemicals used, created, and released at CIPP manufacturing sites. During this study, it became clear to the project team that CIPP contractors, CIPP textbooks, trade association literature, and a popular industry CIPP inspector training course did not make clear the host of chemicals that were being used, created, and released into the environment (or their magnitudes). For this reason, it is recommended agencies who contract for CIPP manufacturing to conduct their own independent environmental testing.
“Communities across the U.S. must address their failing buried infrastructure,” says Dr. Andrew Whelton, associate professor of civil engineering and environmental and ecological engineering. “Certainly, repairing damaged drainage culverts in place is attractive option.”
“These technologies can likely be used without endangering human health or the environment if appropriate controls were implemented,” Whelton says. “Now there’s independent evidence which controls are necessary.”
Purdue University researchers have been providing support to state agencies on ways to reduce culvert lining-caused contamination since 2015.
Additional support has been provided to state and federal public and occupational health agencies, environmental regulatory agencies, lining contractors, municipalities, engineering consulting firms and law enforcement.
In July 2017, the researchers published results about previously unreported worker and public safety risks for CIPP lining and called for new safeguards.
Information about their activities can be found at the CIPP Safety website.
This new study was funded through the U.S. Federal Highway Administration’s pooled fund program, the Virginia Department of Transportation was the study’s lead transportation agency.
Additional study partners included the California Department of Transportation, Kansas Department of Transportation, New York State Department of Transportation, North Carolina Department of Transportation and Ohio Department of Transportation. Twenty-six other states provided information.
For more information, contact Dr. Andrew Whelton, Purdue University, by sending email to: awhelton@purdue.edu.
(Photo: From Purdue University video overview of the study. These and other studies points out the “steam” in the photo can contain harmful chemicals.)
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[Posted: November 26, 2019] www.PaEnvironmentDigest.com
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