Reports and Other Documents
Available at https://doi.org/10.1021/acs.estlett.2c00710 or contact us for a copy
Cured-in-place-pipe (CIPP) is an onsite plastic manufacturing technology used in the U.S. and has not been evaluated for regulatory compliance with federal air pollution laws. The practice involves the discharge of manufacturing waste into the environment. The study goal was to estimate the magnitude of volatile organic compounds (VOCs) discharged into the atmosphere for styrene and nonstyrene composite manufacture and examine low-cost air monitoring sensor reliability. Time-resolved emission analysis revealed that VOC emission was not only isolated to the thermal curing period but also occurred before and after curing. In addition to the styrene monomer, other gas-phase hazardous air pollutants regulated under the Clean Air Act were also emitted. Based on typical CIPP installations, 0.9 to 16.6 U.S. tons of emitted VOCs were estimated for styrene CIPPs, and 0.09 to 1.6 U.S. tons of emitted VOCs were estimated for nonstyrene CIPPs. Because the number and size of CIPPs manufactured in a single community can vary, the total air pollution burden will significantly differ across communities. Low-cost VOC sensors commonly utilized near CIPP manufacturing activities did not accurately quantify styrene and should not be relied upon for that purpose. Up to several thousand-fold detection differences were observed. Regulatory evaluation of CIPP air pollution and PID sensor reliability assessments are recommended.
Available at https://www.neha.org/bystander-chemical-exposures-and-injuries or contact us for a copy
Cured‐in‐place pipes (CIPPs) are plastic liners manufactured inside existing damaged sanitary sewer, storm sewer, and water pipes that extend the service life of host pipes. This process often is conducted in neighborhoods and near roadways. Before, during, and after plastic manufacture, waste materials that include volatile materials are released into the air. Emissions from this manufacturing process can affect outdoor air quality and indoor air quality for buildings connected to the sewer system. We identified key issues and solicited stakeholder feedback to estimate and manage public health risks of CIPP-generated chemical air pollution. A work group representing 13 U.S. agencies and public health associations provided feedback and prioritized public health issues for action. To mitigate potential public and occupational health risks, additional testing and public health educational efforts were recommended. An improved understanding of CIPP chemical exposure pathways, as well as stakeholder needs and interests, is essential.
- In 2022, Dr. Whelton was asked by a community represented by the Advisory Neighborhood Council (ANC) 3F in Washington D.C. to review the DC Water Air Monitoring Plan for a cured-in-place-pipe (CIPP) sewer rehabilitation project. The ANC is a body of D.C. government that advises D.C. government agencies and the D.C. Council on policies and programs that affect their neighborhoods.
- Community members represented by ANC 3F had expressed concerns that DC Water and its agents were not properly protecting the public and the environment from harm where CIPP was planned for use to repair a nearby sewer line. The CIPP manufacturing activities were initially scheduled to begin in 2022 and include steam based CIPP with styrene-resin. During 2022, DC Water decided to instead proceed with hot water based CIPP with nonstyrene resin.
- The Air Monitoring Plan Dr. Whelton reviewed was submitted in late 2022 by DC Water to its local air quality regulator, Department of Energy and the Environment (DOEE).
- During Dr. Whelton's review in collaboration with a community member, 17 deficiencies and some false claims were found. Corrective recommendations also with supporting information were provided so that DC Water could revise and then proceed with an evidence-based air testing plan for their CIPP project. The CIPP practice can likely be used without endangering human health and the environment if appropriate controls were implemented.
- Some conslusions included, but were not limited to, (a) To design an evidence-based air testing plan for public health and environmental protection decisions, chemicals in the resin, byproducts created during manufacture, and emitted into the air must be understood, (b) Any air sampling information collected must be interpretable and the devices must be used properly used, (c) Photoionization detector (PID) levels cited for taking action are arbitrary and have no public health or safety protection basis, and (d) The presence of an odor does not mean a compound present on a material safety data sheet (SDS) is the cause.
- In 2022, Dr. Whelton had offered to connect DC Water with Purdue experts on CIPP to help them anticipate their air testing strategy, but this support was not pursued by DC Water.
Available at https://www.nature.com/articles/s41565-022-01219-9 or contact us for a copy
Nanoplastic particles are inadequately characterized environmental pollutants that have adverse effects on aquatic and atmospheric systems, causing detrimental effects to human health through inhalation, ingestion and skin penetration1,2,3. At present, it is explicitly assumed that environmental nanoplastics (EnvNPs) are weathering fragments of microplastic or larger plastic debris that have been discharged into terrestrial and aquatic environments, while atmospheric EnvNPs are attributed solely to aerosolization by wind and other mechanical forces. However, the sources and emissions of unintended EnvNPs are poorly understood and are therefore largely unaccounted for in various risk assessments4. Here we show that large quantities of EnvNPs may be directly emitted into the atmosphere as steam-laden waste components discharged from a technology commonly used to repair sewer pipes in urban areas. A comprehensive chemical analysis of the discharged waste condensate has revealed the abundant presence of insoluble colloids, which after drying form solid organic particles with a composition and viscosity consistent with EnvNPs. We suggest that airborne emissions of EnvNPs from these globally used sewer repair practices may be prevalent in highly populated urban areas5, and may have important implications for air quality and toxicological levels that need to be mitigated.
Available at https://doi.org/10.1016/j.jclepro.2022.131803 or contact us for a copy
New plastic composites are being manufactured outdoors, inside buried water and sewer pipes. This cured-in-place-pipe (CIPP) practice has been less expensive than other infrastructure repair options, but pollutants discharged during and after plastic manufacture pose environmental and human health problems. The study goal was to better understand how composite manufacturing conditions could be altered to reduce the amount of pollution released. Initiator loading, curing time, and curing pressure were modified for CIPP styrene and non-styrene ("HAP and VOC free") resin based composites. The styrene resin contained 39 wt% volatile organic compounds (VOC) whereas the non-styrene resin contained 4 wt% VOCs. Both resins contained hazardous air pollutants (HAP), endocrine disruptor, and carcinogenic compounds not listed on their safety data sheets. Vacuum pressure prompted greater VOC loss from the resins compared to ambient pressure manufacture. During both pressure manufacturing conditions, less than 1 wt% VOC was released from non-styrene composites into air compared to 8.8 to 26.4 wt% VOC released from styrene composites. VOCs including acetophenone, dibutyl maleate, p,α-dimethylstyrene, ethylbenzene, isopropylbenzene, methacrylic acid, 2-phenyl-2-propanol, styrene, toluene, and m-xylene were present in the non-styrene composite after manufacture. By doubling the styrene composite's initiator loading, styrene and styrene oxide residuals were reduced by 42 and 33 wt%, respectively. Manufacturer recommended conditions for the non-styrene composite resulted in <1 wt% initiator usage. The life cycle environmental impact assessment, which considered only composite VOC residual, predicted that styrene dominantly influenced ecotoxicity and human carcinogenic levels. Modifications to CIPP resin composition and the curing process can reduce environmental and human health impacts.
Available at https://doi.org/10.1016/j.jhazmat.2021.126832 or contact us for a copy
The cured‐in‐place pipe (CIPP) manufacturing process is used to repair buried pipes, and its waste commonly discharged into the air can enter nearby buildings. Exposure can prompt illness and the need for medical care. A mass balance model was applied to estimate indoor styrene concentrations due to intrusion of CIPP emissions through plumbing under different bathroom ventilation conditions. To better understand building contamination and recommend emergency response actions, calculations to estimate chemical intrusion through plumbing were developed. Field reports and study calculations showed that contractor-applied external pressures during plastic manufacture have and can displace plumbing trap water seals. Modeled styrene vapor concentrations that entered the building (1, 300, 1000 ppm) were similar to those measured at CIPP worksites. Modeling revealed that in some cases, bathroom exhaust fan operation during a CIPP project may increase indoor styrene concentrations due to enhanced entrainment of styrene-laden air from the sink and toilet. However, styrene concentrations decreased with increasing air leakage across the bathroom door due to reduced suction from the plumbing system. CIPP waste discharge should be treated as a hazardous material release and can pose a threat to human health. Immediate building evacuation, respiratory protection, provision of medical assistance, source elimination, and building decontamination are recommended.
Available at https://doi.org/10.1039/D0EM00190B or contact us for a copy
The in situ manufacture of cured-in-place-pipe (CIPP) plastic liners in damaged sewer pipes is an emerging mobile source of anthropogenic air pollution. Evidence indicates volatile organic compounds (VOCs) can be released before, during, and after manufacture. The chemical composition of a popular uncured styrene-based CIPP resin was examined, along with the VOCs that remained in the new cured composite. The roles of curing temperature and heating time in waste discharged into the air were examined. Uncured resin contained approximately 39 wt% VOCs. Multiple hazardous air pollutants were present, however, 61 wt% of the uncured resin was not chemically identified. A substantial mass of VOCs (8.87 wt%) was emitted into the air during manufacture, and all cured composites contained about 3 wt% VOCs. Some VOCs were created during manufacture. Curing temperature (65.5-93.3 °C) and heating time (25-100 min) did not cause different composite VOC loadings. High styrene air concentrations inhibited the detection of other VOCs in air. It is estimated that tens of tons of VOCs may be emitted at a single CIPP manufacturing site. Regulators should consider monitoring, and potentially regulating, these growing mobile air pollution and volatile chemical product sources as they are operating in urban and rural areas often in close proximity to residential and commercial buildings.
Available at https://doi.org/10.1177%2F0021998320913988 or contact us for a copy
Ultraviolet light cured-in-place pipe is a popular trenchless rehabilitation technology used to repair existing buried pipelines without soil excavation. A polymer composite liner is manufactured directly in the field. After curing is complete, the new liner is placed in service to convey flowing water. Long-term water exposure has the potential to degrade the fiber reinforced cured-in-place pipe liners. Like other composites, liner hygrothermal stability could be a major challenge, especially for undercured materials. The objective of this study was to investigate the effect of aggressive environmental conditions such as water, salt solution, and simulated concrete pore solution at 50℃ on cured-in-place pipe liner mechanical and thermo-mechanical performance. Liners were exposed to aqueous solutions ranging from a typical exposure environment to a very aggressive alkaline environment. Cured-in-place pipe liner samples were collected from New York storm sewer installation sites. Specimens were assessed for the degree of curing as determined by differential scanning calorimetry and TGA. Samples were then immersed in aforementioned solutions for investigating the stability of the liners as a function of degree of cure. Both interlaminar shear strength and thermo-mechanical properties significantly differed based on the degree of cure. Cured-in-place pipe liner mechanical and thermo-mechanical properties were significantly impacted by water, salt, and pore solutions exposure. Long-term exposure to salt and alkaline environments may have a detrimental effect on the performance of cured-in-place pipe liners and desires additional scrutiny.
Available at https://doi.org/10.1080/08958378.2019.1621966 or contact us for a copy
US water infrastructure is in need of widespread repair due to age-related deterioration. Currently, the cured-in-place (CIPP) procedure is the most common method for water pipe repair. This method involves the on-site manufacture of a new polymer composite plastic liner within the damaged pipe. The CIPP process can release materials resulting in occupational and public health concerns. To understand hazards associated with CIPP-related emission exposures, an in vitro toxicity assessment was performed.
Available at https://doi.org/10.1177/0021998319839132 or contact us for a copy
Cured-in-place pipe (CIPP), a popular trenchless technology, has gained wide attention for drinking water, sewerage and storm water pipe rehabilitation because of its ease of installation. Here, the physical and thermal properties of steam-cured PET felt/polyester resin CIPPs were studied. 1H NMR and GC-MS analysis was performed to identify the unreacted volatile organic compounds in cured CIPPs and results were compared to uncured resin and laboratory cured liner characterizations. Results indicated that organic chemicals in cured CIPP altered the mechanical properties and may be leached out with water. Significantly, lower porosity, density and amount of unreacted volatile organic compounds were much less in the CIPP's inner layer as compared to its outer layer. Water conditioning was conducted to investigate the influence of water on CIPP physical and mechanical properties. No changes were observed for density and porosity for either the CIPP's inner and outer layer; however, the flexural modulus increased slightly due to unreacted organic chemical leaching from the CIPPs.
Available at https://doi.org/10.1016/j.jhazmat.2019.02.097 or contact us for a copy
Cured-in-place-pipes (CIPP) are plastic liners chemically manufactured inside existing damaged sewer pipes. They are gaining popularity in North America, Africa, Asia, Europe, and Oceania. Volatile and semi-volatile organic compound (VOC/SVOC) emissions from storm sewer CIPP installations were investigated at a dedicated outdoor research site. Tedlar bag, sorbent tube, and photoionization detector (PID) air sampling was conducted for five steam-CIPP installations and was coupled with composite characterizations. New CIPPs contained up to 2.21 wt% volatile material and only 6–31% chemical mass extracted per CIPP was identified. Each 6.1 m [20 ft] liner contained an estimated 5–10 kg [11–22 lbs] of residual chemical. Extracted chemicals included hazardous air pollutants and suspected and known carcinogens that were not reported by others. These included monomers, monomer oxidation products, antioxidants, initiator degradation products, and a plasticizer. PID signals did not accurately represent styrene air concentration differing sometimes by 10s- to 1000s-fold. Multiple VOCs found in air samples likely affected PID responses. Styrene (>86.4 ppmv) and methylene chloride (>1.56 ppmv) air concentrations were likely greater onsite and phenol was also detected. Additional studies are needed to examine pollutant emissions so process monitoring can be improved, and environment impacts and associated human exposures can be minimized.
Available at https://docs.lib.purdue.edu/jtrpaffdocs/30/ or contact us for a copy
Millions of miles of existing U.S. storm water culverts are critical for roadway safety but much of this infrastructure requires repair. State departments of transportation (DOT) are increasingly choosing to rehabilitate culverts with spray-on and cured-in-place pipe (CIPP) lining processes. These culvert lining practices involve the manufacture of a new plastic liner inside a damaged culvert. DOTs are selecting these outdoor plastic manufacturing methods partly to avoid open-trench excavation, which can cause traffic disruption and work zone traffic safety issues. This study was conducted to better understand current knowledge about culvert lining caused environmental contamination, final product quality, and recommend improved construction specifications, project oversight, and testing requirements to limit undesirable consequences. Literature reviews, a survey of construction specifications and special provisions for 32 transportation agencies, as well as field- and bench-scale testing for CIPP projects in California, New York, and Virginia, were completed. During this project, the safety of workers, transportation agency employees, and the general public at lining installation sites, was raised as a concern by state and federal agencies. Due to previously unreported hazards which were encountered at multiple CIPP field sites, the provision of worksite safety recommendations for DOTs was added to this study. Recommendations are provided for spray-on lining and CIPP lining culvert repair projects that can (1) limit environmental contamination, (2) improve worksite safety, and (3) aid DOTs in better understanding the quality of their new liners.
Available at https://www.sciencedirect.com/science/article/pii/S0269749118329804 or contact us for a copy
Storm water culverts are integral for U.S. public safety and welfare, and their mechanical failure can cause roadways to collapse. To repair these buried assets, ultraviolet (UV) light cured-in-place-pipes (CIPP) are being installed. Chemical emission and residual material left behind from the installation process was investigated in New York and Virginia. Samples of an uncured resin tube and field-cured styrene-based resin CIPPs were collected and analyzed. Also collected were air and water samples before, during, and after installations. Chemicals were emitted into air because of the installation and curing processes. Particulates emitted into the air, water, and soil contained fiberglass, polymer, and contaminants, some of which are regulated by state-level water quality standards. The uncured resin tube contained more than 70 chemical compounds, and 19 were confirmed with analytical standards. Compounds included known and suspected carcinogens, endocrine disrupting compounds, hazardous air pollutants, and other compounds with little aquatic toxicity data available. Compounds (14 of 19 confirmed) were extracted from the newly installed CIPPs, and 11 were found in water samples. Aqueous styrene (2.31 mg/L), dibutyl phthalate (12.5 μg/L), and phenol (16.7 μg/L) levels exceeded the most stringent state water quality standards chosen in this study. Styrene was the only compound that was found to have exceed a 48 h aquatic toxicity threshold. Newly installed CIPPs contained a significant amount volatile material (1.0–6.8 wt%). Recommendations provided can reduce chemical emission, as well as improve worksite and environmental protection practices. Recommended future research is also described.
Available at https://onlinelibrary.wiley.com/doi/full/10.1002/awwa.1042 or contact us for a copy
Cured-in-place-pipe (CIPP) technology has been used to rehabilitate sanitary sewer, storm sewer, and drinking water pipes. However, utilities, regulators, and health officials have raised environmental, occupational, and public health concerns regarding chemical emissions into air and water. To better understand emissions into water, available literature was reviewed. Water contamination has been documented in 10 states and Canada due to the release of uncured resin, solvents, manufacturing byproducts, and wastes during and after construction. Odor, fish kill, and drinking water contamination incidents have been reported. The few field- and bench-scale studies available show that a variety of VOCs and SVOCs have been released into water and contamination was detected for several months. CIPP waste was acutely toxic to aquatic organisms. Chemical release is likely influenced by formulation, installation, and environmental conditions. CIPP installation and inspection recommendations were suggested. Studies are needed to develop evidence-based construction and monitoring practices to minimize risks.
Available online at http://blogs.cdc.gov/niosh-science-blog/2017/09/26/cipp/
Available at http://pubs.acs.org/doi/10.1021/acs.estlett.7b00237 or contact us for a copy.
Chemical emissions were characterized for steam-cured cured-in-place-pipe (CIPP) installations in Indiana (sanitary sewer) and California (stormwater). One pipe in California involved a low-volatile organic compound (VOC) non-styrene resin, while all other CIPP sites used styrene resins. In Indiana, the uncured resin contained styrene, benzaldehyde, butylated hydroxytoluene (BHT), and unidentified compounds. Materials emitted from the CIPP worksites were condensed and characterized. An emitted chemical plume in Indiana was a complex multiphase mixture of organic vapor, water vapor, particulate (condensable vapor and partially cured resin), and liquid droplets (water and organics). The condensed material contained styrene, acetone, and unidentified compounds. In California, both styrene and low-VOC resin condensates contained styrene, benzaldehyde, benzoic acid, BHT, dibutyl phthalate, and 1-tetradecanol. Phenol was detected only in the styrene resin condensate. Acetophenone, 4-tert-butylcyclohexanol, 4-tert-butylcyclohexanone, and tripropylene glycol diacrylate were detected only in the low-VOC condensate. Styrene in the low-VOC condensate was likely due to contamination of contractor equipment. Some, but not all, condensate compounds were detected in uncured resins. Two of four California styrene resin condensates were cytotoxic to mouse alveolar type II epithelial cells and macrophages. Real-time photoionization detector monitoring showed emissions varied significantly and were a function of location, wind direction, and worksite activity.
Until more CIPP air monitoring and chemical toxicity data are available, the recommendation is that persons at or near CIPP sites
(1) minimize dermal and inhalation exposures,
(2) monitor emissions,
(3) use appropriate personal protective equipment (section S2), and
(4) capture emissions and confirm this by monitoring.
Response available at https://engineering.purdue.edu/CIPPSafety/Incorrect-Assertions-About-CIPP-Study.pdf.
1) Statements issued and distributed by NASSCO, Incorporated and distributed by other parties have incorrectly described the Purdue University study. The researchers addressed some of the incorrect information in this document.
2) Again, the Purdue University researchers offered to work with those interested in better understanding and improving worker and public safety at and near CIPP water pipe repair sites.
3) Researchers again recommended that additional investigations should be conducted to understand emissions from CIPP installations, and to determine the occupational, public health, and environmental risks.
4) Due to human health concerns, the researchers directed persons who install CIPP to contact the National Institute for Standards and Health (NIOSH) to request Health Hazard Evaluations.
5) Due to human health concerns, the researchers directed persons who visit CIPP worksites such as municipal employees and consulting engineer employees, to contact NIOSH for assistance.
6) The Purdue University researchers stated that CIPP technology could likely be used without endangering human health or the environment if appropriate safeguards were instituted.
1) Professional Engineers who select, use, and oversee CIPP installations, have a professional and ethical duty to “hold paramount the safety, health and welfare of the public” and make only “truthful and objective statements.”
2) Engineers trained in the use of CIPP often are not warned about potentially immediately dangerous to life and health (IDLH) conditions at CIPP worksites or past air testing studies.
3) Stringent and enforced specification requirements should include proper personal protective equipment (PPE), setback distances, worksite air monitoring, capture and proper disposal of all emissions and waste, as well as the immediate reporting of complaints to health department and fire departments.