Seasonal Fluctuations in Nitrate Levels Can Trigger Lead Solder Corrosion Problems in Drinking Water.

After a utility switched its source water from ground to surface water in 2017, first draw water lead levels spiked due to increased lead solder corrosion that could not be explained by existing knowledge. When lead release was not adequately reduced with a 90:10 orthophosphate/polyphosphate corrosion inhibitor blend or even high levels of 100% orthophosphate, an in-depth investigation of possible causes revealed a strong correlation between 90th percentile lead and seasonal fluctuations in surface water nitrate levels. Complementary bench-scale studies that tested new copper coupons with lead solder and harvested pipes from a worst case home verified a strong relationship between nitrate and elevated lead. Lead release in the presence of nitrate became increasingly erratic with time, resulting in the spalling of large lead solder particulates up to 7 mm in length into the water. Lead levels were occasionally >1000 ppb in homes and >100000 ppb in the bench experiments with harvested pipe. Orthophosphate was unable to sufficiently reduce lead levels below the action level during periods with high nitrate levels in the bench studies. Water utilities and regulators should proactively consider possible unintended consequences of higher nitrate levels on lead release when changing source waters or during seasonal runoff events.

Introducing the "Corona Curtain": an innovative technique to prevent airborne COVID-19 exposure during emergent intubations.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic places healthcare workers at risk of exposure to the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Emergency department (ED) staff are particularly vulnerable when managing patients with acute respiratory distress due to the aerosolization of the virus during endotracheal intubation. A simple and innovative intubation tent was designed with the intent of decreasing the risk of accidental viral transmission from emergent intubations during the COVID-19 pandemic. PRESENTATION OF TECHNIQUE: The materials and assembly process of the novel "Corona Curtain" are described in technical detail, with the intent of allowing other providers to template the concept at their respective facilities. RESULTS: A total of 36 intubation tents were mounted in the ED at the Medical Center of Aurora, Colorado, on April 7, 2020, and thereafter consistently used for all intubations during the ongoing COVID-19 outbreak. The cost of raw materials and labor for the initial assembly averaged US $ 8.00 per construct. The price of the single-use plastic cover is variable depending on the vendor source. CONCLUSION: The new "Corona Curtain" was designed to improve the safety of ED staff when performing urgent/emergent intubations during the current COVID-19 pandemic. The concept can easily be adopted to other patient care areas, including perioperative and intensive care units. Future validation studies are needed to determine the safety and efficacy of the intubation tents by quantifying the pre-/post-intubation exposure through "point-of-care" SARS-CoV-2 testing once these resources are more widely available.

The role of wastewater treatment in protecting water supplies against emerging pathogens.

Traditionally, regulators, dischargers, and even water suppliers believed that wastewater discharge meeting the levels of 200 cfu/ 100 mL of fecal coliforms in wastewater effluent was sufficient to protect against downstream microbial effects. However, these beliefs are now being challenged by emerging pathogens that are resistant to standard water and wastewater treatment processes, exhibit extended survival periods in the environment, can adversely affect sensitive subpopulations, and require extremely low doses for human infection. Based on this new information, it is estimated that discharges of emerging pathogens from conventional wastewater treatment plants as far as 160 km upstream and cumulative amounts of wastewater discharge ranging from 2 to 20 ML/d have the potential to reach a water supply intake in a viable state at significant concentrations that could exceed regulatory limits for drinking water supplies, increase endemic risk from drinking water, and/or require additional drinking water treatment. Wastewater dischargers may be able mitigate this potential effect and achieve upwards of 6 log combined removal and inactivation of emerging pathogens to mitigate drinking water effects by using alternative treatment processes, such as filtration or UV light disinfection, or optimizing these processes based on site-specific conditions.

Recent water quality trends in the Schuylkill River, Pennsylvania, USA: a preliminary assessment of the relative influences of climate, river discharge and suburban development.

Climate, flow rate and land use are all known drivers of water quality in river systems, but determining the relative influences of these factors remains a significant challenge for aquatic science and management. Long-term data from the Schuylkill River at Philadelphia is assessed here in an attempt to ascertain the separate and combined influence of these major drivers on water quality in a developed watershed. Water quality measures including nutrients, conservative solutes and bacteria all elicited distinct seasonal patterns driven primarily by river discharge. Mass transport rates of sodium and chloride have increased with time, and were elevated in winter, presumably as a function of road salt deposition. A steady increase in developed land area in the watershed has occurred in recent decades, which allowed the use of time as a surrogate parameter for regional development in the construction of multiple factor linear models predicting the relative influences of precipitation, river discharge and developed land area on river water quality. Linear models predicting annually averaged water quality measures showed the effects of precipitation, discharge and developed land area to be of nearly equal importance in regulating levels of conductivity, alkalinity, sodium, and chloride in the river. Models predicting water quality variables for discrete samples demonstrated that river flow was the major determinant of daily variability in alkalinity, conductivity, hardness and calcium levels, while still resolving the highly significant influence of watershed development on water quality. Increases in solute transport in the Schuylkill River in recent decades appear to be the direct result of modern suburban development in the watershed.