or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Although laboratory investigations have been used to assess the movement of PPCPs in soil systems, we are unaware of any multiyear studies that have assessed the fate and transport of PPCPs under controlled irrigated conditions in the fi eld. As such, we conducted a lysimeter study to assess the fate and transport of 13 PPCPs detected in recycled water used to ABSTRACT An environmentally acceptable alternative to discharging recycled water to rivers, lakes, and other bodies of water is to use the water for irrigation of large areas of turfgrass. Such waters contain pharmaceuticals and personal care products (PPCPs), of which, some may have high mobility in irrigated soil-plant systems, potentially impacting groundwater resources. To determine the movement of 13 PPCPs under irrigated turfgrass conditions, a fi eld-based lysimeter study was conducted. Aft er 745 d of monitoring, 9 of the 13 compounds were detected in drainage samples. Th e compounds with the highest detection rate in the drainage water were sulfamethoxazole and primidone in both soil types (100% in the loamy sand soil for both compounds and 50 and 65%, respectively, in the sandy loam soil) and carbamazepine in the loamy sand soil (50%). Factors infl uencing the movement of these compounds varied based on the compound and the imposed treatments. In the case of primidone, 94% of the variability in the mass discharge could be accounted for by taking into account the number of unsaturated pore volumes draining, the sand content, and the redox potential at 105 cm. Th e highest mass fl ux, scaled on a hectare basis, was recorded for sulfamethoxazole (0.25 g ha -1 yr -1 ). Based on our results, restricting the use of recycled water based solely on the presence of PPCPs should only be a consideration at sites where soils are extremely sandy and irrigation regimes are not based on an evapotranspiration feedback approach.

Irrigators in arid and semiarid regions that use reuse water must maintain positive leaching fractions (LFs) to minimize salt buildup in root zones. However, with the continuous feed of NO3-N in reuse water, imposing LFs can also lead to greater downward movement of NO3-N. It is therefore essential that deep movement of NO3-N be assessed relative to nitrogen loading under such conditions. We conducted a long-term monitoring program on nine golf course fairways in southern Nevada over a 1600-d period. The fairways were predominantly bermudagrass [Cynodon Dactylon (L.) Pers.; 35 of 36 site × years] overseeded with perennial ryegrass (Lolium perenne L.; 8 of 9 courses). Courses were irrigated with fresh water, reuse water (tertiary treated municipal sewage effluent), or transitioned to reuse water during the study. Solution extraction cups were inserted at depths of 15, 45, 75, and 105 cm on fairways and sampled and analyzed for NO3-N on a monthly basis. Distribution patterns of NO3-N varied from site to site. Concentrations exceeding 100 mg·L−1 were observed at the 105-cm depth on all three long-term reuse courses. On the transitional courses, 72% of the variation in the yearly average NO3-N concentrations at the105-cm depth could be accounted for based on knowing the amount of fertilizer nitrogen (N) applied, the amount of reuse N applied, and the LF (Y = –42.5 + 0.18 fertilizer N + 0.26 reuse N –62.0 LF). Highest N fertilizer applications occurred on transition courses with little or no reduction in N applications after courses had transitioned to reuse water (pretransition courses 394 + 247 kg·ha−1 N/year versus posttransition courses 398 + 226 kg·ha−1 N/year). The results of this study indicate a need for a more scientific approach to N management on reuse irrigated courses.

A field study was conducted on a small urban watershed (residential and golf course dominated) in southern Nevada to assess the concentration and speciation of selenium (Se) in a series of drain lines and monitoring wells and to quantify the mass discharge of Se from the drain system. Water samples were collected on a monthly basis and analyzed for total Se, selenate (SeO4 (=)) and selenite (SeO3 (=)). In addition, where possible, flow was assessed as was, temperature, redox potential, pH, dissolved oxygen (DO) along with all major cations and anions. The data were then modeled with PhreeqC to identify selenium speciation. Results revealed a SeO4 (=) dominated system with SeO4 (=) concentrations ranging from 13 to 62 ppb. In the monitoring wells, 66 % of the variation in the total Se concentration could be described based on depth to groundwater, temperature and sulfate concentrations (P < 0.001). In particular, higher total Se concentrations were predicted for shallower depth to groundwater, suggesting the solubilization of Se evapo-concentrates near the surface could be reduced by lowering water tables. The highest of all correlations was found between SeO4 (=) concentrations (↑) and the sodium (↑) and DO (↑) concentrations in the monitoring wells (R (2) = 0.77, P < 0.001). An excellent curvilinear relationship was found between total Se and the electrical conductivity in the water (R (2) = 0.73, P < 0.001). Based on the Se data and time line identified in this study, high concentrations of Se could be expected to drain from this area for many years to come, with salinity acting as a good proxy for Se concentration. In the drain lines, Se concentrations were found to be invariant to flow (P > 0.05). Flow discharge from the main drain system to the Las Vegas Wash was estimated at 559 acre feet during the 1 year study period. This flow was estimated to carry 4,203 Mg of salts 6.71 Mg of nitrate-N and 27.1 kg of total Se.

or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Grattan et al., 2007). Irrigators must realize that irrigating with waters that possess elevated levels of soluble salts will lead to salt buildup over time in the root zone, although the rate of buildup is signifi cantly lower if appropriate leaching occurs on an annual basis. As such, the LF should be viewed as a concentration factor (Ayers and Westcot, 1985;Tanji et al., 2007). On large turfgrass areas in the more arid regions of the United States, high environmental demand during summer months oft en restricts the ability of irrigators to incorporate a significant LF into their irrigation scheduling, due to the increased irrigation times required and the likelihood of restricted play because of wet conditions. Under such conditions, leaching typically is confi ned to the fall-winter overseed period (Devitt et al., 2007).In a companion study by the authors (Wright et al., 2012), the fate and transport of pharmaceuticals in turfgrass systems irrigated with recycled water was assessed. In that study, tight water balances were maintained in lysimeters packed with two diff erent soil types (BC and NLV) that were either planted to hybrid bermudagrass [Tifway, Cynodon dactylon (L.)] and over seeded with perennial ryegrass (Palmer lll, Lolium perenne L.) or left bare and irrigated with recycled water at LF's of 0.05 or 0.25. Th ese LFs were selected to represent low and high leaching conditions for Las Vegas golf courses (Devitt et al., 2007). Th e objective of our research was to determine the infl uence that recycled water had on drainage, crop/ evaporation coeffi cients, and salt and N displacement in soil turfgrass systems irrigated over a 745-d monitoring period. ABSTRACTRecycled water is used extensively in the southwestern United States as an alternative source of water for irrigation. However, using such waters require proper management to avoid excessive salt loading and N leaching. A study was conducted to assess the impact of recycled water on the water and salt status of Boulder City loamy sand (BC) and North Las Vegas sandy loam (NLV) soils left bare or planted to turfgrass with leaching fractions (LF = drainage volume/irrigation volume) of 0.05 or 0.25. It took as long as 375 d for drainage to occur in one of the NLV 0.05 LF lysimeters, with a prediction of 820 d for the fi rst pore volume of drainage (PV = drainage volume/unsaturated soil water volume in storage). Crop coeffi cients (K c ) and evaporation coeffi cients (K e ) revealed a signifi cant soil × LF interaction (P < 0.05) with a statistical separation between turfgrass grown in the NLV soil under a 0.25 LF (K c = 1.17) vs. all other turfgrass treatments (K c = 0.99) and also with regards to K e (0.91 vs. 0.52). Displacement of salts and specifi c ions were linked to PVs of drainage and soil type. In the case of the NLV lysimeters, the Na leached was related to the Mg leached in a sigmoidal fashio...

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