Drinking water vulnerability in less-populated communities in Texas to wastewater-derived contaminants

Abstract

De facto potable reuse occurs when treated wastewater is discharged upstream of drinking water treatment plants (DWTPs) and can lead to contaminants of emerging concern (CECs) occurring in potable water. Our prior research, focusing on larger communities that each serve >10,000 people across the USA, indicates that elevated de facto reuse (DFR) occurs in Texas, and thus we added to our model DWTPs serving smaller communities to understand their vulnerability to CECs. Here, we show that twothirds of all surface water intakes in Texas were impacted by DFR at levels exceeding 90% during even mild droughts, and under average streamflow DFR levels range between 1 and 20%. DWTPs serving lower population communities (<10,000 people) have higher DFR levels, and fewer than 2% of these communities have advanced technologies (e.g., ozone, activated carbon) at DWTPs to remove CECs. Efforts to improve water quality in these less populated communities are an important priority. The model approach and results can be used to identify prioritization for monitoring and treatment of CECs, including in underserved communities, which normally lack knowledge of their impacts from DFR occurring within their watersheds.npj Clean Water (2019) 2:19 ; https://doi.

Co-Occurrence of Bromine and Iodine Species in US Drinking Water Sources That Can Impact Disinfection Byproduct Formation

“…There is nearly 4× higher bromide ion and up to 30× higher iodine concentrations in treated wastewater than untreated drinking waters. Therefore, the occurrence of Br and I species in wastewater effluents can have implications for downstream source waters; unplanned or indirect wastewater reuse frequently occurs with dilution factors less than 10-fold. − Our analysis suggests drinking water sources impacted by upstream wastewater discharges would benefit from monitoring for Br – plus individual inorganic species and total iodine to comprehensively assess the risk of forming I-DBPs.…”

Temporal variations of de facto wastewater reuse and disinfection by-products in public water systems in the Shenandoah River watershed, USA

“…De facto reuse based on average streamflow has been estimated as at least 1% for approximately 50% of U.S. drinking water treatment plant (DWTP) intakes (i.e., 1% was the median contribution of wastewater flow to U.S. DWTPs and provides a realistic reference point that would be applicable to a broad range of such plants). Others have examined the impacts of de facto reuse on small communities (Nguyen & Westerhoff 2019) and found that DWTPs serving them have higher levels of de facto reuse.…”

“…De facto reuse based on the proportion of wastewater in any stream varies with time, as wastewater discharge flows and streamflow vary (Merritt 1983;Corbitt 1999;Fernandez et al 2008;Daelman et al 2015). Municipal wastewater discharge flows are generally considered directly related to the number of people served by a wastewater treatment plant (WWTP).…”

“…Municipal wastewater discharge flows are generally considered directly related to the number of people served by a wastewater treatment plant (WWTP). Minimum design ranges for U.S. WWTPs have been reported as 0.95-1.5 cubic meters (m 3 )/day/person (250-400 gallons (gals)/day/person) (Merritt 1983). WWTP flow is also influenced by infiltration and inflow (I&I) associated with heavy rain events.…”

Comparison of Advanced Oxidation Processes for the Degradation of Maprotiline in Water—Kinetics, Degradation Products and Potential Ecotoxicity

“…Particular attention should be paid to compounds that are scarcely biodegradable, such as pharmaceuticals, personal care products, hormones, food additives, artificial sweeteners, pesticides, and dyes among others [4][5][6]. Due to their distinct chemical properties (polarity, functional groups, solubility,…) and potential persistence, CECs are poorly removed by conventional wastewater treatment methodologies and are thus frequently detected in the wastewater treatment plant (WWTP) effluents [7]. These effluents act as a constant low-level source of such substances to the environment.…”