Contamination of Potable Water by Permeation of Plastic Pipe

Abstract

Sites of seven incidents of plastic pipe permeation were visited between July 1986 and December 1987, and samples of soil, pipe material, and pipe water were collected. In addition, a comprehensive literature review was undertaken to document other cases of permeation. This work demonstrated that the majority of permeation incidents were associated with gross soil contamination in the area surrounding the pipe. Soil contamination occurred mainly after pipe installation, suggesting that soil analysis prior to pipe installation will not significantly decrease the number of incidents. The occurrence of about half the incidents in low risk areas indicates that limiting plastic pipe use to these areas will not be effective in preventing permeation.

Permeation of BTEX compounds through HDPE pipes under simulated field conditions

“…Toluene and xylenes were the major compounds detected in the pipe water, whereas the permeation of benzene through pipes was insignificant. These observations were consistent with results reported from other permeation incidents (Holsen et al, 1991a). In three reported incidents involving gasoline, toluene permeated to the greatest degree, followed by xylenes, ethylbenzene, and benzene (in the same order as shown in Figure 5, part A), whereas in the other cases associated with gasoline, xylenes permeated more readily, followed by toluene and ethylbenzene (in the same order shown in Figure 5, parts B and C).…”

“…The higher susceptibility of small‐size pipes to permeation is supported by the findings of a study of real permeation incidents that reported all permeation incidents for service lines were associated with pipe ≤ 1 in. in diameter (Holsen et al, 1991a). For the same bulk concentration, the concentration of contaminant in pipe water decreases with increasing pipe size, mainly because of the increase of wall thickness and the resulting decrease in permeation rate.…”

“…Four levels of gasoline‐contaminated soil were prepared by spiking 1 kg of the sand–topsoil mixture with known amounts of premium gasoline and mixing the soil by rotating the soil container for one week. The volumetric moisture content of the soil was adjusted to approximately 10%, which was above the water content of soils equilibrated at a relative humidity > 98% (Holsen et al, 1991b). The amounts of BTEX sorbed onto the four soils were determined using methanol extraction and analyzed by gas chromatography.…”

“…Park and co‐workers (1991) reported that organic chemicals that do not readily permeate PB pipes when present alone can have their permeability enhanced considerably when they are mixed with highly permeable organic chemicals. In addition, soil type and characteristics may have a significant effect on the permeation of organic compounds through pipe materials by implicitly determining the effective availability for permeation (Holsen et al, 1991b).…”

Critical considerations for the accelerated ageing of high-density polyethylene potable water materials

“…Chemical interaction is very important to potable water pipe stakeholders because it can impact water safety, aesthetics, and structural integrity. Chemical interaction can be examined by immersing polymer samples in neat contaminant solution [67][68][69] or by exposing them to dilute aqueous solutions [70][71][72][73]. Most accelerated ageing techniques [7,9,11,14,16,17,22,25,43] Source: Dietrich and WheltonÓ2008 Awwa Research Foundation.…”