Spatiotemporal variability in microbial quality of western US agricultural water supplies

A multistate study

Melissa L. Partyka, Ronald F. Bond, Jennifer A. Chase, Edward R Atwill

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

In 2011, the US Congress passed the Food Safety Modernization Act, which tasks the US Food and Drug Administration to establish microbiological standards for agricultural water. However, little data are available for the microbiological quality of surface water irrigation supplies. During the 2015 irrigation season, we conducted a baseline study on the microbial water quality of large irrigation districts in California (n = 2) and Washington (n = 4). Monthly samples (n = 517) were analyzed for bacterial indicators (fecal coliforms, enterococci, and Escherichia coli) and pathogens (Salmonella spp., E. Coli O157, and non-O157 Shiga toxin-producing E. Coli [STEC]). Although there was a high degree of variability (m ? SD = 59.13 ? 106.0), only 11% of samples (56/517) exceeded 126 colony-forming units (CFU) 100 mL-1, and only six samples exceeded 410 CFU 100 mL-1. Two volumes of water were collected for pathogen analysis (1 L and 10 L); prevalence of Salmonella in 10-L samples (68/149) was nearly double of that found in 1-L samples (132/517). We found STEC during ~9% of sampling events (58/517); serotypes O26 and O45 were the most common at 31 and 26%, respectively. Pathogens were not associated with exceedance of the regulatory threshold, yet the odds of detecting Salmonella increased approximately threefold (odds ration [O.R.] = 3.14, p < 0.0001) for every log increase in turbidity. Microbiological outcomes were highly district-specific, suggesting drivers of water quality vary across spatiotemporal scales. The true risk of contamination of produce from irrigation water supplies remains unknown, along with the optimal monitoring strategy to improve food safety. Copyright c

Original languageEnglish (US)
Pages (from-to)939-948
Number of pages10
JournalJournal of Environmental Quality
Volume47
Issue number5
DOIs
StatePublished - Sep 1 2018

Fingerprint

Water supply
Irrigation
Escherichia coli
Salmonella
Pathogens
water supply
irrigation
Food safety
food safety
pathogen
toxin
Water quality
water quality
Turbidity
fecal coliform
Modernization
Surface waters
modernization
turbidity
Water

ASJC Scopus subject areas

  • Environmental Engineering
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution
  • Management, Monitoring, Policy and Law

Cite this

Spatiotemporal variability in microbial quality of western US agricultural water supplies : A multistate study. / Partyka, Melissa L.; Bond, Ronald F.; Chase, Jennifer A.; Atwill, Edward R.

In: Journal of Environmental Quality, Vol. 47, No. 5, 01.09.2018, p. 939-948.

Research output: Contribution to journalArticle

@article{df6a83ac74f843b9b16b5f1a181c9371,
title = "Spatiotemporal variability in microbial quality of western US agricultural water supplies: A multistate study",
abstract = "In 2011, the US Congress passed the Food Safety Modernization Act, which tasks the US Food and Drug Administration to establish microbiological standards for agricultural water. However, little data are available for the microbiological quality of surface water irrigation supplies. During the 2015 irrigation season, we conducted a baseline study on the microbial water quality of large irrigation districts in California (n = 2) and Washington (n = 4). Monthly samples (n = 517) were analyzed for bacterial indicators (fecal coliforms, enterococci, and Escherichia coli) and pathogens (Salmonella spp., E. Coli O157, and non-O157 Shiga toxin-producing E. Coli [STEC]). Although there was a high degree of variability (m ? SD = 59.13 ? 106.0), only 11{\%} of samples (56/517) exceeded 126 colony-forming units (CFU) 100 mL-1, and only six samples exceeded 410 CFU 100 mL-1. Two volumes of water were collected for pathogen analysis (1 L and 10 L); prevalence of Salmonella in 10-L samples (68/149) was nearly double of that found in 1-L samples (132/517). We found STEC during ~9{\%} of sampling events (58/517); serotypes O26 and O45 were the most common at 31 and 26{\%}, respectively. Pathogens were not associated with exceedance of the regulatory threshold, yet the odds of detecting Salmonella increased approximately threefold (odds ration [O.R.] = 3.14, p < 0.0001) for every log increase in turbidity. Microbiological outcomes were highly district-specific, suggesting drivers of water quality vary across spatiotemporal scales. The true risk of contamination of produce from irrigation water supplies remains unknown, along with the optimal monitoring strategy to improve food safety. Copyright c",
author = "Partyka, {Melissa L.} and Bond, {Ronald F.} and Chase, {Jennifer A.} and Atwill, {Edward R}",
year = "2018",
month = "9",
day = "1",
doi = "10.2134/jeq2017.12.0501",
language = "English (US)",
volume = "47",
pages = "939--948",
journal = "Journal of Environmental Quality",
issn = "0047-2425",
publisher = "ASA/CSSA/SSSA",
number = "5",

}

TY - JOUR

T1 - Spatiotemporal variability in microbial quality of western US agricultural water supplies

T2 - A multistate study

AU - Partyka, Melissa L.

AU - Bond, Ronald F.

AU - Chase, Jennifer A.

AU - Atwill, Edward R

PY - 2018/9/1

Y1 - 2018/9/1

N2 - In 2011, the US Congress passed the Food Safety Modernization Act, which tasks the US Food and Drug Administration to establish microbiological standards for agricultural water. However, little data are available for the microbiological quality of surface water irrigation supplies. During the 2015 irrigation season, we conducted a baseline study on the microbial water quality of large irrigation districts in California (n = 2) and Washington (n = 4). Monthly samples (n = 517) were analyzed for bacterial indicators (fecal coliforms, enterococci, and Escherichia coli) and pathogens (Salmonella spp., E. Coli O157, and non-O157 Shiga toxin-producing E. Coli [STEC]). Although there was a high degree of variability (m ? SD = 59.13 ? 106.0), only 11% of samples (56/517) exceeded 126 colony-forming units (CFU) 100 mL-1, and only six samples exceeded 410 CFU 100 mL-1. Two volumes of water were collected for pathogen analysis (1 L and 10 L); prevalence of Salmonella in 10-L samples (68/149) was nearly double of that found in 1-L samples (132/517). We found STEC during ~9% of sampling events (58/517); serotypes O26 and O45 were the most common at 31 and 26%, respectively. Pathogens were not associated with exceedance of the regulatory threshold, yet the odds of detecting Salmonella increased approximately threefold (odds ration [O.R.] = 3.14, p < 0.0001) for every log increase in turbidity. Microbiological outcomes were highly district-specific, suggesting drivers of water quality vary across spatiotemporal scales. The true risk of contamination of produce from irrigation water supplies remains unknown, along with the optimal monitoring strategy to improve food safety. Copyright c

AB - In 2011, the US Congress passed the Food Safety Modernization Act, which tasks the US Food and Drug Administration to establish microbiological standards for agricultural water. However, little data are available for the microbiological quality of surface water irrigation supplies. During the 2015 irrigation season, we conducted a baseline study on the microbial water quality of large irrigation districts in California (n = 2) and Washington (n = 4). Monthly samples (n = 517) were analyzed for bacterial indicators (fecal coliforms, enterococci, and Escherichia coli) and pathogens (Salmonella spp., E. Coli O157, and non-O157 Shiga toxin-producing E. Coli [STEC]). Although there was a high degree of variability (m ? SD = 59.13 ? 106.0), only 11% of samples (56/517) exceeded 126 colony-forming units (CFU) 100 mL-1, and only six samples exceeded 410 CFU 100 mL-1. Two volumes of water were collected for pathogen analysis (1 L and 10 L); prevalence of Salmonella in 10-L samples (68/149) was nearly double of that found in 1-L samples (132/517). We found STEC during ~9% of sampling events (58/517); serotypes O26 and O45 were the most common at 31 and 26%, respectively. Pathogens were not associated with exceedance of the regulatory threshold, yet the odds of detecting Salmonella increased approximately threefold (odds ration [O.R.] = 3.14, p < 0.0001) for every log increase in turbidity. Microbiological outcomes were highly district-specific, suggesting drivers of water quality vary across spatiotemporal scales. The true risk of contamination of produce from irrigation water supplies remains unknown, along with the optimal monitoring strategy to improve food safety. Copyright c

UR - http://www.scopus.com/inward/record.url?scp=85055418347&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85055418347&partnerID=8YFLogxK

U2 - 10.2134/jeq2017.12.0501

DO - 10.2134/jeq2017.12.0501

M3 - Article

VL - 47

SP - 939

EP - 948

JO - Journal of Environmental Quality

JF - Journal of Environmental Quality

SN - 0047-2425

IS - 5

ER -