Total Maximum Daily Loads and <i>Escherichia coli</i> Trends in Texas Freshwater Streams

Schramm, Michael P.; Gitter, Anna; Gregory, L.

doi:10.1111/j.1936-704x.2022.3374.x

Cited by 5 publications

(3 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To maintain public health, effluent sewer system construction in the Dongshan River watershed, which is designed to reduce CSOs, must be promptly completed. In addition, the Taiwanese government should implement total maximum daily loads (TMDLs) to conduct river waterbodies in the Dongshan River watershed that exceed the allowable E. coli criteria (Schramm et al., 2022). For example, the effluent discharge standards for E. coli are enhanced to improve river water quality (Kao et al., 2003).…”

Section: Discussionmentioning

confidence: 99%

Seasonal assessment of risks to canoeists’ health in a Taiwanese recreational river

Liu

Jang

2023

Risk Analysis

View full text Add to dashboard Cite

Canoeing is the most favorite recreational activity in several Taiwanese rivers. However, river water frequently contains elevated levels of pathogenic Escherichia coli, which has adverse effects on human health. This study adopted a quantitative microbial risk assessment to analyze seasonal risks to canoeists’ health in the Dongshan River, Taiwan. First, river E. coli concentrations were statistically analyzed to determine the seasonal distributions. The exposure duration (ED) was determined by field observations. To propagate the parametric uncertainty, Monte Carlo simulation was employed to model the probability distributions of seasonal pathogenic E. coli levels, ingestion rates, and ED for athletes. Finally, the beta‐Poisson dose–response model was implemented to determine seasonal health risks for canoeists. The study results indicated that the health risks in infection probability ranged from 0.5 × 10−3 to 8.8 × 10−3 illnesses/person/day for tourists and 1.2 × 10−3 to 7.7 × 10−3 illnesses/person/day for athletes. The health risks in the Lizejian Bridge area for tourists exceeded an acceptable level suggested by the U.S. Environmental Protection Agency, 8 × 10−3 illnesses/person/day, in spring for an ED of 2 h/day, and the health risks for tourists and athletes approached this level in spring and winter for an ED exceeding or equaling 1.5 h/day. According to sensitivity analysis, the geometric standard deviation of river E. coli levels was the most sensitive parameter affecting seasonal risks to canoeists’ health. To protect canoeists’ health, effluent sewer systems, best management practices, and total maximum daily loads should be promptly implemented in this watershed.

show abstract

Section: Discussionmentioning

confidence: 99%

Seasonal assessment of risks to canoeists’ health in a Taiwanese recreational river

Liu

Jang

2023

Risk Analysis

View full text Add to dashboard Cite

show abstract

“…Due to the concerning increases in eutrophication associated parameters in Lavaca Bay and other Texas estuaries ( Bugica, Sterba-Boatwright & Wetz, 2020 ), and the desire to quantify linkages between environmental outcomes and on the ground management actions ( Schramm, Gitter & Gregory, 2022 ) there is a strong need for reliable estimates of pollutant loadings and responses along the Texas coast. Within Texas, statewide water quality monitoring programs have focused on collection of ambient condition data.…”

Section: Discussionmentioning

confidence: 99%

“…There are ongoing efforts between local, state, and federal agencies to address water quality impairments in the freshwater portions of the Lavaca Bay watershed ( Jain & Schramm, 2021 ; Schramm et al, 2018 ; Berthold, Olsovsky & Schramm, 2021 ). However, on a statewide scale, these approaches have shown limited success and emphasize a need for improved methods to assess and link management actions with downstream water quality ( Schramm, Gitter & Gregory, 2022 ). Such methods could help identify and replicate effective water quality management actions across the state .…”

Section: Introductionmentioning

confidence: 99%

Linking watershed nutrient loading to estuary water quality with generalized additive models

Schramm

2023

PeerJ

View full text Add to dashboard Cite

Evaluating estuary water quality responses to reductions (or increases) in nutrient loading attributed to on the ground management actions can be challenging due to the strong influence of environmental drivers on nutrient loads and non-linear relationships. This study applied generalized additive models to calculate watershed nutrient loads and assess responses in estuary water quality to seasonally-adjusted freshwater inflow and flow-adjusted nutrient loads in Lavaca Bay, Texas. Lavaca Bay is a secondary embayment on the Texas coast displaying early potential for eutrophication and water quality degradation. Use of flow-adjusted nutrient loads allowed the study to evaluate the response in water quality to changes in nutrient loads driven by anthropogenic sources. Cross-validation indicated that, despite data constraints, semiparametric models performed well at nutrient load prediction. Based on these models, delivered annual nutrient loads varied substantially from year to year. In contrast, minimal changes in flow-normalized loads indicate that nutrient loadings were driven by natural variation in precipitation and runoff as opposed to changes in management of nonpoint sources. Models indicated no evidence of long-term changes in dissolved oxygen or chlorophyll-a within Lavaca Bay. However, site specific long-term increases in both organic and inorganic nitrogen are concerning for their potential to fuel eutrophication. Further analysis found freshwater inflow had strong influences on nutrient and chlorophyll-a concentrations but there was no evidence that changes in watershed nutrient loading explained additional variation in dissolved oxygen and limited evidence that watershed nutrient loadings explained chlorophyll-a concentrations. In addition to providing a baseline assessment of watershed nutrient loading and water quality responses in the Lavaca Bay watershed, this study provides methodological support for the use of semiparametric models in load regression models and estuary assessments.

show abstract

Coastal wetlands as sources of Escherichia coli to the nearshore of Lake Ontario

Harrow-Lyle,

Chomicki,

Kirkwood

2024

Journal of Great Lakes Research

View full text Add to dashboard Cite

Total Maximum Daily Loads and Escherichia coli Trends in Texas Freshwater Streams

Cited by 5 publications

References 44 publications

Seasonal assessment of risks to canoeists’ health in a Taiwanese recreational river

Seasonal assessment of risks to canoeists’ health in a Taiwanese recreational river

Linking watershed nutrient loading to estuary water quality with generalized additive models

Coastal wetlands as sources of Escherichia coli to the nearshore of Lake Ontario

Contact Info

Product

Resources

About