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This paper presents findings from a side-by-side operational comparison of granular road salt (RS) and MeltDown 20 (MD) deicing chemicals for snow and ice control from the perspective of "the maintenance worker in the truck." The field test site, near Canyon, Texas, was divided into sixteen 305 m (1,000 ft) sections that were either untreated controls or received treatment with RS or MD at nominal Texas Department of Transportation (TxDOT) application rates of 85 kg/lane km (300 lb/lane mile) and 42 kg/lane km (150 lb/lane mile), respectively. Three storms met pre-established criteria for snow accumulation, and field test sections were subject to cycles of plowing, deicing treatment, and slushing. Video and still-image data facilitated estimation of visible pavement, and vehicle-based decelerometer tests measured pavement friction. Overall results showed that granular RS outperformed MD in 5/20 data events (25%) and RS outperformed untreated control in 9/20 data events (45%). In contrast, MD never outperformed RS and outperformed control in only 5/20 data events (25%). Further, TxDOT maintenance management data indicate the operational cost to apply MD (corrosion-inhibited) is 3.5× higher than RS (noninhibited), raising questions about cost-effectiveness given the road, climate, and temperature conditions characteristic of the north Texas latitude. [ABSTRACT FROM AUTHOR]

Trade-offs between water-resource depletion and salinization need to be understood when promoting water-conservative irrigation practices. This companion paper assesses impacts of groundwater-fed irrigation on soil water and groundwater quality using data from the southern High Plains (SHP). Unsaturated zone soil samples from 13 boreholes beneath irrigated agroecosystems were analyzed for water-extractable anions. Salt accumulation in soils varies with irrigation water quality, which ranges from low salinity in the north (median Cl: 21 mg/L) to higher salinity in the south (median Cl: 180 mg/L). Large Cl bulges under irrigated agroecosystems in the south are similar to those under natural ecosystems, but they accumulated over decades rather than millennia typical of natural ecosystems. Profile peak Cl concentrations (1200-6400 mg/L) correspond to irrigation efficiencies of 92-98% with respect to drainage and are attributed to deficit irrigation with minimal flushing. Perchlorate (ClO4) also accumulates under irrigated agroecosystems, primarily from irrigation water, and behaves similarly to Cl. Most NO3-N accumulation is below the root zone. Groundwater total dissolved solids (TDS) have increased by ≤960 mg/L and NO3-N by ≤9.4 mg/L since the early 1960s. Mobilization of salts that have accumulated under irrigated agroecosystems is projected to degrade groundwater much more in the future because of the essentially closed-basin status of the aquifer, with discharge occurring primarily through irrigation pumpage. TDS are projected to increase by an additional 2200 mg/L (median), ClO4 by 21 μg/L, and NO3-N by 52 mg/L. Water and salt balances should be considered in irrigation management in order to minimize salinization issues. [ABSTRACT FROM AUTHOR]

Investigates the perchlorate uptake in aquatic and terrestrial macrophytes from multiple streams surrounding a perchlorate-contaminated site, the Naval Weapons Industrial Reserve Plant at McGregor, Texas. Release potential of perchlorate in deciduous leaves trapped in leaf litter traps; Preponderance of laboratory data on perchlorate uptake in plants; Use of parrot-feather.

This paper presents findings from a side-by-side field comparison of the effectiveness of sodium chloride-based road salt brine (RSB) and magnesium chloride-based Meltdown Apex™ liquid (MDA) as anti-icing chemicals for snow and ice control associated with winter roadway maintenance. The study was sponsored by the Texas Department of Transportation (TxDOT) to support operational decision-making for chemical treatment selections based on the perspective of pavement conditions observed by "the maintenance worker in the truck." The field test site was a portion of rural service road near Canyon, Texas, located at latitude 35° N. The site was divided into eight 305 m sections that were treated with RSB at 141 l/lane km, MDA at 47 l/lane km, or left untreated for control. Two storm events at the test site during Winter 2014–2015 met pre-established research criteria for snow accumulation and other variables. Test sections were subjected to cycles of plowing, slushing, and additional anti-icing liquid treatment. Digital video data and still image (photo) data were collected throughout the storm events to allow estimation of visible pavement, and vehicle-based decelerometer tests were used to measure pavement friction. Overall results from multiple performance measures indicated comparable effectiveness of RSB and MDA at the applied rates. It was also noted that application of MDA on dry pavement prior to the storm events significantly reduced the pavement friction. • This anti-icing field study compared road salt (RSB) vs. magnesium chloride (MDA). • Video, image, and decelerometer data offered consistent field performance measures. • RSB and MDA anti-icing liquids showed comparable field performance. • For Texas, inhibited MDA costs eight times more to apply than non-inhibited RSB. • Pre-snow applications of MDA reduced pavement surface friction (slicker surface). [ABSTRACT FROM AUTHOR]