Name: vegetated treatment systems for removing contaminants associated with surface water toxicity in agriculture and urban runoff
Uploaded: 2017-05-15T12:30:00
Description: Watch this Scientific Journal Video about Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff at JoVE.com

Funding for the work described here came from the California Department of Pesticide Regulation and the California Department of Water Resources.

1. Urban Bioswale Efficacy Monitoring
<ol>
	<li>Storm Water Sampling
	<ol>
		<li>Sample 4 L of pre-treatment stormwater leaving the parking lot as it enters the bioswale inlet, and then 4 L of post-treatment stormwater as it leaves the bioswale through the 4&#34; outlet drain.</li>
		<li>Using local weather predictions, collect samples at the beginning, middle, and end of the storm&#39;s hydrograph. Composite the samples to characterize runoff variability during the storm event.</li>
		<li>Collect 1.3 ...

<ol>
	<li>Anderson, B. S., Hunt, J. W., Markewicz, D., Larsen, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Toxicity in California Waters, Surface Water Ambient Monitoring Program. , (2011).</li><li>Anderson, B. S., Phillips, B. M., Voorhees, J. P., Siegler, K., Tjeerdema, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioswales+reduce+contaminants+associated+with+toxicity+in+urban+stormwater.">Bioswales reduce contaminants associated with toxicity in urban stormwater.</a> Environ Toxicol Chem. 35 (12), 3124-3134 (2016).</li><li>Anderson, B. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pesticide+and+toxicity+reduction+using+an+integrated+vegetated+treatment+system.">Pesticide and toxicity reduction using an integrated vegetated treatment system.</a> Environ Toxicol Chem. (30), 1036-1043 (2011).</li><li>Phillips, B. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Mitigation Strategies for Reducing Aquatic Toxicity from Chlorpyrifos in Cole Crop Irrigation Runoff. , (2014).</li><li>U.S. EPA. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Method 1640: Determination of Trace Elements in Ambient Waters by On-Line Chelation Pre-concentration and Inductively Coupled Plasma-Mass Spectrometry. , (1995).</li><li>U.S. EPA. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Methods for organic chemical analysis of municipal and industrial wastetwater, Method 625- Base/neutrals and acids. , (1984).</li><li>U.S. EPA. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> , (1993).</li><li>Johnson, H. M., Domagalski, J. L., Saleh, D. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trends+in+Pesticide+Concentrations+in+Streams+of+the+Western+United+States.">Trends in Pesticide Concentrations in Streams of the Western United States.</a> J Am Water Resour Assoc. 47 (2), 265-286 (1993).</li><li>Siegler, K., Phillips, B. M., Anderson, B. S., Voorhees, J. P., Tjeerdema, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temporal+and+spatial+trends+in+sediment+contaminants+associated+with+toxicity+in+California+watersheds.">Temporal and spatial trends in sediment contaminants associated with toxicity in California watersheds.</a> Environ Poll. , 1-6 (2015).</li><li>U.S. EPA. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Methods for measuring acute toxicity of effluents and receiving water to freshwater and marine organisms. , (2002).</li><li>Bailey, H. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Joint+acute+toxicity+of+diazinon+and+chlorpyrifos+to+Ceriodaphnia+dubia.">Joint acute toxicity of diazinon and chlorpyrifos to Ceriodaphnia dubia.</a> Environ Toxicol Chem. 16, 2304-2308 (1997).</li><li>Supowit, S., Sadaria, A. M., Reyes, E. J., Halden, R. U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+balance+of+fipronil+and+total+toxicity+of+fipronil-related+compounds+in+process+streams+during+conventional+wastewater+and+wetland+treatment.">Mass balance of fipronil and total toxicity of fipronil-related compounds in process streams during conventional wastewater and wetland treatment.</a> Environ Sci Technol. 50 (3), 1519-1526 (2016).</li><li>Stang, C., Bakanov, N., Schulz, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experiments+in+water-macrophyte+systems+to+uncover+the+dynamics+of+pesticide+mitigation+processes+in+vegetated+surface+waters/streams.">Experiments in water-macrophyte systems to uncover the dynamics of pesticide mitigation processes in vegetated surface waters/streams.</a> Environ Sci Pollut Res. , (2015).</li><li>Schulz, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Field+studies+on+exposure,+effects,+and+risk+mitigation+of+aquatic+nonpoint-source+insecticide+pollution:+A+review.">Field studies on exposure, effects, and risk mitigation of aquatic nonpoint-source insecticide pollution: A review.</a> J Environ Qual. 33 (2), 419-448 (2004).</li><li>Moore, M. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transport+and+fate+of+atrazine+and+lambda-cyhalothrin+in+a+vegetated+drainage+ditch+in+the+Mississippi+Delta.">Transport and fate of atrazine and lambda-cyhalothrin in a vegetated drainage ditch in the Mississippi Delta.</a> Agric Ecosyst Environ. 87, 309-314 (2001).</li><li>Phillips, B. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Effects+of+the+Landguard+A900+Enzyme+on+the+Macroinvertebrate+Community+in+the+Salinas+River,+California,+United+States+of+America.">The Effects of the Landguard A900 Enzyme on the Macroinvertebrate Community in the Salinas River, California, United States of America.</a> Arch Environ Contam Toxicol. 70 (2), 231-240 (2016).</li><li>Han, W., Fang, J., Liu, X., Tang, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Techno-economic+feasibility+evaluation+of+a+combined+bioprocess+for+fermentative+hydrogen+production+from+food+waste.">Techno-economic feasibility evaluation of a combined bioprocess for fermentative hydrogen production from food waste.</a> Bioresource Technology. , 107-112 (2016).</li><li>Solomon, K. R., Giddings, J. M., Maund, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probabilistic+risk+assessment+of+cotton+pyrethroids:+I.+Distributional+analysis+of+laboratory+aquatic+toxicity+data.">Probabilistic risk assessment of cotton pyrethroids: I. Distributional analysis of laboratory aquatic toxicity data.</a> Environ Toxicol Chem. 20, 652-659 (2001).</li><li>Weston, D. P., Lydy, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toxicity+of+the+Insecticide+Fipronil+and+Its+Degradates+to+Benthic+Macroinvertebrates+of+Urban+Streams.">Toxicity of the Insecticide Fipronil and Its Degradates to Benthic Macroinvertebrates of Urban Streams.</a> Environ Sci Tech. , (2014).</li><li>Voorhees, J. P., Anderson, B. S., Phillips, B. M., Tjeerdema, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbon+treatment+as+a+method+to+remove+imidacloprid+from+agriculture+runoff.">Carbon treatment as a method to remove imidacloprid from agriculture runoff.</a> Bull Environ Contam Toxicol. , (2017).</li></ol>

The practices described in this protocol are intended as final steps in an overall strategy to remove pollutants in agriculture irrigation and stormwater runoff. Use of bioswales and other urban green-infrastructure LID practices are intended as a final piece of the puzzle to remove contaminants in runoff before they reach adjacent receiving waters. This protocol emphasizes methods to monitor urban bioswales to determine treatment efficacy for removing toxicity associated with urban contaminants, with emphasis on current...

Surface water toxicity is prevalent in California watersheds and decades of monitoring have shown that toxicity is often due to pesticides and other contaminants1. The primary sources of surface water contamination are stormwater and irrigation runoff from urban and agriculture sources. As waterbodies are listed as degraded due to contaminants and the toxicity is identified from urban and agricultural sources, water quality regulators partner with state and federal funding sources to implement practices to reduce contaminant loading. Green infrastructure is being promoted in California urban watersheds to reduce flooding and increase the recovery of stormwater through infiltration and storage. While Low Impact Development (LID) designs are being mandated for new construction in many regions, few studies have monitored the efficacy of these systems beyond measurements of conventional contaminants like dissolved solids, metals, and hydrocarbons. More intensive monitoring has recently evaluated reductions in chemical concentrations and chemical loading responsible for surface water toxicity, and to directly determine whether bioswales reduce toxicity of runoff. This has shown that bioswales are effective at removing toxicity associated with some contaminant classes2, but additional research is required for emerging chemicals of concern.
Vegetated treatment systems are also being implemented in agriculture watersheds in California, and these have been shown to be effective at reducing pesticides and other contaminants in agriculture irrigation runoff3,4. These systems represent components of a suite of approaches to reduce contaminant loading to surface waters. Because they are intended to mitigate contaminants responsible for surface water toxicity, a key component of the implementation process is monitoring to ensure their long-term effectiveness. Monitoring includes both chemical analyses of chemicals of concern, as well as toxicity testing with sensitive indicator species. This article describes protocols and monitoring results for an urban parking lot bioswale and an agricultural vegetated drainage ditch system.
The design attributes of a typical parking lot bioswale, such as may be used to treat storm runoff in a typical mixed-use urban shopping parking area depend on the area being treated. In the example described here, 53,286 square feet of asphalt create an impervious surface area that drains to a swale, which consists of 4,683 square feet of landscaping. To accommodate runoff from this surface area, a 215 feet long flat-bottom, semi-V shape channel comprises the swale with a side slope less than 50% and a longitudinal slope of 1% (Figure 1). This swale comprises three layers including native bunch grass planted in 6 inches of topsoil, layered over 2.5 feet of compacted subgrade. Stormwater flows from parking areas to multiple entry points along the swale. The water infiltrates the vegetated area, then permeates the subgrade and drains into a 4-inch perforated drain. This system drains water through a system plumbed to an adjacent wetland that eventually drains into a local creek.

<table border="0" cellpadding="0" cellspacing="0" width="679">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">HOBO tipping-bucket digital logger rain gauge&#160;</td>
			<td style="width:177px;">Onset Computer Co., Bourne MA, USA)</td>
			<td style="width:119px;">Onset RG3</td>
			<td style="width:167px;">Rain gauge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Mechanical geared pulse flow meter&#160;</td>
			<td style="width:177px;">Seametrics Inc., Kent WA</td>
			<td>Seametrics MJ-R</td>
			<td>Flow meter for measuring bioswale outlet flow</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Filtrexx SafteySoxx</td>
			<td style="width:177px;">Filtrexx Co. - info@filtrexx.com</td>
			<td style="width:119px;">SafetySoxx</td>
			<td>perforated synthetic cloth for granulated activated carbon and compost</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Granulated activated carbon&#160;</td>
			<td style="width:177px;">Evoqua - Siemens Corp., Oakland CA</td>
			<td style="width:119px;">AC380</td>
			<td>GAC for agriculture irrigation water treatment</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Digital flow meters&#160;</td>
			<td style="width:177px;">Seametrics Inc. Kent WA</td>
			<td style="width:119px;">Ag2000; WMP101</td>
			<td>Flow meters for agriculture irrigation treatment system monitoring</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Data Loggers</td>
			<td>Campbell Scientific Inc., Logan, UT</td>
			<td style="width:119px;">CR1000</td>
			<td>Data loggers for recording flow data</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Peristaltic pumps for composite sampling</td>
			<td style="width:177px;">Omega Engineering Inc. Stamford CT</td>
			<td>Omegaflex FPU-122-12VDC&#160;</td>
			<td>Pumps for composite sampling</td>
		</tr>
	</tbody>
</table>

vegetated treatment systems for removing contaminants associated with surface water toxicity in agriculture and urban runoff

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may be treated with simple systems designed to promote sorption of contaminants to vegetation and soils and promote infiltration. Two example systems are described: a bioswale treatment system for urban stormwater treatment, and a vegetated drainage ditch for treating agriculture irrigation runoff. Both have similar attributes that reduce contaminant loading in runoff: vegetation that results in sorption of the contaminants to the soil and plant surfaces, and water infiltration. These systems may also include the integration of granulated activated carbon as a polishing step to remove residual contaminants. Implementation of these systems in agriculture and urban watersheds requires system monitoring to verify treatment efficacy. This includes chemical monitoring for specific contaminants responsible for toxicity. The current paper emphasizes monitoring of current use pesticides since these are responsible for surface water toxicity to aquatic invertebrates.

Urban Bioswale Efficacy
During the 18.5 h of the storm, 1.52&#34; of rain was recorded by the rain gauge, and this resulted in 50,490 gallons of water flowing from the parking lots into the bioswale. Of this total volume, 5,248 gallons were recorded by the outlet flow meter, resulting in a total infiltration of 90% of the stormwater that flowed into the bioswale. The bioswale reduced all of the chemicals monitored. Total suspended ...

Watch this Scientific Journal Video about Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff at JoVE.com

Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff

This article summarizes the design attributes and the effectiveness of treatment systems that treat urban stormwater and agriculture irrigation runoff to remove pesticides and other contaminants associated with aquatic toxicity.

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may ...

The overall goal of these procedures is to combine chemical analysis with freshwater invertebrate toxicity tests to evaluate how well vegetated treatment systems remove current-use pesticides from urban storm water, and agriculture irrigation runoff. This approach is intended to answer whether standard remediation practices are effective at protecting surface water quality from contaminants. And to determine the appropriate monitoring components for evaluating effectiveness of management practices.The main advantage of these procedures is that they couple toxicity test protocols with chemical monitoring of in-field remediation techniques, designed to reduce loading of pesticides in surface waters. Bryn Phillips and Michael Cahn will demonstrate components of an integrated vegetated treatment system, designed to remove pesticides and other contaminants from agricultural runoff. Jennifer Voorhees will demonstrate three toxicity test protocols, used to monitor the treatment system.The vegetated drainage ditch, used in the current example, is 152 meters long, and has a semi V-shaped cross-section width of five meters at the top, and one meter depth. The ditch vegetation is a combination of native grass species, primarily seeded with red fescue. The vegetated ditch is augmented with compost filters and carbon filters.Filters are constructed from tubular mesh sleeves that are two meters long and twenty centimeters in diameter. Fill each carbon sleeve with 30 liters of granulated, activated carbon. And fill each compost sleeve with 15 kilograms each of partially decomposed yard waste from any clean source, such as a local landfill.Install the filters in different sections of the vegetated ditch, as displayed in the text protocol. Anchor the sleeves to the ditch bottom with wire stakes on the upstream edge. Then, place a 2.5 meter long, six inch wide, section of pine board on the downstream edge of each of the sleeves.Dig the pine boards into the two sides, and bottom of the channel, to minimize water bypassing and undercutting the carbon sleeves. The boards will also provide vertical support to maximize the water contact time with the carbon. The efficacy of the integrated ditch system can be tested by creating simulated agricultural runoff, using groundwater mixed with suspended sediment and spiked with a model pesticide.Since neurotoxic pesticides, such as organophosphates, pyrethroids, and neonicotinoids, have recently been linked to surface water toxicity, treatment systems and monitoring programs should emphasize these pesticide classes. Monitor the inlet flow rate with a digital meter, and data logger. Use the data to quantify total volume of the runoff water applied to the ditch inlet.Construct a weir at the outlet of the ditch, and plumb it with an outlet pipe connected to a digital flow meter and data logger. Program the data loggers to activate peristaltic pumps located at the inlet, and at various stations below the inlet of the ditch, to collect composite subsamples of runoff into stainless steel containers at five minute intervals. Transfer composite samples of runoff water from trials into amber glass bottles at the end of each runoff trial.Maintain the samples on ice at four degrees Celsius for later toxicity and chemical analysis, as described in the text protocol. Due to time constraints, we have emphasized an integrated vegetated ditch for treating pesticides and agricultural runoff. The design and monitoring principles applied to this system also apply to urban storm water treatment using bioswales, as discussed in the manuscript.Prepare composited inlet and outlet vegetated ditch water samples for conducting toxicity tests using three test species, following modified US Environmental Protection Agency acute and chronic test protocols. Prior to setting up exposures, measure the dissolved oxygen, PH, and conductivity of a subsample of each sample, using appropriate meters and electrodes. Also, measure unionized ammonia using a spectrophotometer.Next, conduct acute 96 hour survival tests, with the cladoceran Ce.dubia. Expose five Ce.dubia neonates in each of five replicates of inlet and outlet stormwater samples. Replicates consist of 20 milliliter scintillation vials containing 15 milliliters of test solution.Renew the Ce.dubia test daily by feeding neonates a mixture of yeast, Cerophyll, trout chow, and Selenastrum algae two hours prior to renewal. Then, transfer the organisms to a fresh sample. Record the total number of surviving neonates daily.Also, conduct acute 10 day survival tests with the amphipod H.azteca. Expose 10 seven day-to 14 day-old amphipods to each of five replicates. Replicates consist of 300 milliliter glass beakers, containing 100 milliliters of test solution.Count the number of surviving amphipods daily, and renew 50%of the test solution every 48 hours. Feed each beaker every 48 hours with 1.5 milliliters of YCT after the renewal. To conduct chronic 10 day survival and growth tests with the midge C.dilutus, expose 12 seven day-old animals in each of four replicates.Replicates consist of 300 milliliter glass beakers, containing 200 milliliters of test solution, and five milliliters of sand, as the substrate for tube-building by the larvae. Renew 50%of the test solution every 48 hours. Feed each beaker daily with an increasing amount of fish food slurry, from four grams per liter of fish food slurry.After counting the final survival of C.dilutus, measure the growth of the surviving organisms as ash-free dry weight. Compare final Ce.dubia survival after 96 hours of exposure to inlet and outlet vegetated ditch samples to their survival in moderately-hard control water, using a t-test. Use the same procedures to compare final survival of H.azteca, and the final survival and growth of C.Dilutus.Representative results of the vegetated treatment of agriculture irrigation runoff, showed that this system is effective at reducing pesticide and toxicity. The average chlorpyrifos loading was reduced by 98%at a flow rate of 3.2, and by 94%at a flow rate of 6.3 liters per second. Toxicity was eliminated in two of the three trials at the lower flow rate, and one of the three trials at the higher flow rate.Reductions of toxicity and pesticides and other contaminants were also observed in bioswale treatment of storm water. Pyrethroid pesticides were greatly reduced in storm water, and associated toxicity to the amphipod, H.azteca, was also reduced. Conversely, the concentration of fipronil sulfone was not reduced by bioswale treatment, and neither was toxicity to the midge, C.Dilutus.Water quality regulators and researchers use aquatic toxicity testing to evaluate the capacity of surface waters to support aquatic life. Data generated through decades of monitoring in California has shown that most toxicity to invertebrates is caused by pesticides. Environmental regulators in California are implementing policies to reduce loading of pesticides from storm water, and agriculture runoff.These include the promotion of treatment systems, designed to reduce loading of current-use pesticides from these sources. Visual demonstration of the toxicity test protocols should reinforce the concept that monitoring the efficacy of these treatment systems needs to use test species and protocols that are sensitive to current-use pesticides. We have shown that vegetated systems are a cost-effective solution for treating pesticides in agricultural runoff.Addition of granulated, activated carbon to these systems has been shown to remove residual pesticides not removed by vegetation. Monitoring the effectiveness of these systems using targeted chemical analysis, and appropriate toxicity test protocols, will ensure that these practices are protecting aquatic ecosystems.

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Research

JoVE Journal

Environment

Design and Construction of an Urban Runoff Research Facility

As the urban population increases, so does the area of irrigated urban landscape. Summer water use in urban areas can be 2-3x winter base line water use due to increased demand for landscape irrigation. Improper irrigation practices and large rainfall events can result in runoff from urban landscapes which has potential to carry nutrients and sediments into local streams and lakes where they may contribute to eutrophication. A 1,000 m2 facility was constructed which consists of 24 individual 33.6 m2 field plots, each equipped for measuring total runoff volumes with time and collection of runoff subsamples at selected intervals for quantification of chemical constituents in the runoff water from simulated urban landscapes. Runoff volumes from the first and second trials had coefficient of variability (CV) values of 38.2 and 28.7%, respectively. CV values for runoff pH, EC, and Na concentration for both trials were all under 10%. Concentrations of DOC, TDN, DON, PO4-P, K+, Mg2+, and Ca2+ had CV values less than 50% in both trials. Overall, the results of testing performed after sod installation at the facility indicated good uniformity between plots for runoff volumes and chemical constituents. The large plot size is sufficient to include much of the natural variability and therefore provides better simulation of urban landscape ecosystems.

This paper describes the design, construction, and function of a 1,000 m2 facility containing 24 individual 33.6 m2 field plots equipped for measuring total runoff volumes with time and collection of runoff subsamples at selected intervals for quantification of chemical constituents in the runoff water from simulated home lawns.

As the urban population increases, so does the area of irrigated urban landscape. Summer water use in urban areas can be 2-3x winter base line water use ...

A Protocol for Conducting Rainfall Simulation to Study Soil Runoff

Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The objective of this study was to characterize the effects of antecedent soil moisture content on the fate and transport of surface applied commercial urea, a common form of nitrogen (N) fertilizer, following a rainfall event that occurs within 24&#160;hr&#160;after fertilizer application. Although urea is assumed to be readily hydrolyzed to ammonium and therefore not often available for transport, recent studies suggest that urea can be transported from agricultural soils to coastal waters where it is implicated in harmful algal blooms. A rainfall simulator was used to apply a consistent rate of uniform rainfall across packed soil boxes that had been prewetted to different soil moisture contents. By controlling rainfall and soil physical characteristics, the effects of antecedent soil moisture on urea loss were isolated. Wetter soils exhibited shorter time from rainfall initiation to runoff initiation, greater total volume of runoff, higher urea concentrations in runoff, and greater mass loadings of urea in runoff. These results also demonstrate the importance of controlling for antecedent soil moisture content in studies designed to isolate other variables, such as soil physical or chemical characteristics, slope, soil cover, management, or rainfall characteristics. Because rainfall simulators are designed to deliver raindrops of similar size and velocity as natural rainfall, studies conducted under a standardized protocol can yield valuable data that, in turn, can be used to develop models for predicting the fate and transport of pollutants in runoff.

A rainfall simulator was used to apply a consistent rate of uniform rainfall to packed soil boxes in a study of the fate and transport of urea, a nonpoint source environmental contaminant. Under uniform soil and rainfall conditions, antecedent soil moisture content exerted strong control over urea loss in surface runoff.

Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The ...

A Whole Cell Bioreporter Approach to Assess Transport and Bioavailability of Organic Contaminants in Water Unsaturated Systems

Bioavailability of contaminants is a prerequisite for their effective biodegradation in soil. The average bulk concentration of a contaminant, however, is not an appropriate measure for its availability; bioavailability rather depends on the dynamic interplay of potential mass transfer (flux) of a compound to a microbial cell and the capacity of the latter to degrade the compound. In water-unsaturated parts of the soil, mycelia have been shown to overcome bioavailability limitations by actively transporting and mobilizing organic compounds over the range of centimeters. Whereas the extent of mycelia-based transport can be quantified easily by chemical means, verification of the contaminant-bioavailability to bacterial cells requires a biological method. Addressing this constraint, we chose the PAH fluorene (FLU) as a model compound and developed a water unsaturated model microcosm linking a spatially separated FLU point source and the FLU degrading bioreporter bacterium Burkholderia sartisoli RP037-mChe by a mycelial network of Pythium ultimum. Since the bioreporter expresses eGFP in response of the PAH flux to the cell, bacterial FLU exposure and degradation could be monitored directly in the microcosms via confocal laser scanning microscopy (CLSM). CLSM and image analyses revealed a significant increase of the eGFP expression in the presence of P. ultimum compared to controls without mycelia or FLU thus indicating FLU bioavailability to bacteria after mycelia-mediated transport. CLSM results were supported by chemical analyses in identical microcosms. The developed microcosm proved suitable to investigate contaminant bioavailability and to concomitantly visualize the involved bacteria-mycelial interactions.

A whole cell bioreporter assay with Burkholderia sartisoli RP037-mChe was developed to detect fractions of an organic contaminant (i.e., fluorene) available for bacterial degradation after active transport by mycelia bridging air-filled pores in a water unsaturated model system.

Bioavailability of contaminants is a prerequisite for their effective biodegradation in soil. The average bulk concentration of a contaminant, however, is ...

Preparation and Testing of Impedance-based Fluidic Biochips with RTgill-W1 Cells for Rapid Evaluation of Drinking Water Samples for Toxicity

This manuscript describes how to prepare fluidic biochips with Rainbow trout gill epithelial (RTgill-W1) cells for use in a field portable water toxicity sensor. A monolayer of RTgill-W1 cells forms on the sensing electrodes enclosed within the biochips. The biochips are then used for testing in a field portable electric cell-substrate impedance sensing (ECIS) device designed for rapid toxicity testing of drinking water. The manuscript further describes how to run a toxicity test using the prepared biochips. A control water sample and the test water sample are mixed with pre-measured powdered media and injected into separate channels of the biochip. Impedance readings from the sensing electrodes in each of the biochip channels are measured and compared by an automated statistical software program. The screen on the ECIS instrument will indicate either "Contamination Detected" or "No Contamination Detected" within an hour of sample injection. Advantages are ease of use and rapid response to a broad spectrum of inorganic and organic chemicals at concentrations that are relevant to human health concerns, as well as the long-term stability of stored biochips in a ready state for testing. Limitations are the requirement for cold storage of the biochips and limited sensitivity to cholinesterase-inhibiting pesticides. Applications for this toxicity detector are for rapid field-portable testing of drinking water supplies by Army Preventative Medicine personnel or for use at municipal water treatment facilities.

This manuscript describes how to prepare fluidic biochips with Rainbow trout gill epithelial cells for use in a field portable electric cell-substrate impedance sensor. The protocol for running a rapid drinking water toxicity test with the sensor is also described.

This manuscript describes how to prepare fluidic biochips with Rainbow trout gill epithelial (RTgill-W1) cells for use in a field portable water toxicity ...

A Duplex Digital PCR Assay for Simultaneous Quantification of the Enterococcus spp. and the Human Fecal-associated HF183 Marker in Waters

This manuscript describes a duplex digital PCR assay (EntHF183 dPCR) for simultaneous quantification of Enterococcus spp. and the human fecal-associated HF183 marker. The EntHF183 duplex dPCR (referred as EntHF183 dPCR hereon) assay uses the same primer and probe sequences as its published individual quantitative PCR (qPCR) counterparts. Likewise, the same water filtration and DNA extraction procedures as performed prior to qPCR are followed prior to running dPCR. However, the duplex dPCR assay has several advantages over the qPCR assays. Most important, the dPCR assay eliminates the need for running a standard curve and hence, the associated bias and variability, by direct quantification of its targets. In addition, while duplexing (i.e. simultaneous quantification) Enterococcus and HF183 in qPCR often leads to severe underestimation of the less abundant target in a sample, dPCR provides consistent quantification of both targets, whether quantified individually or simultaneously in the same reaction. The dPCR assay is also able to tolerate PCR inhibitor concentrations that are one to two orders of magnitude higher than those tolerated by qPCR. These advantages make the EntHF183 dPCR assay particularly attractive because it simultaneously provides accurate and repeatable information on both general and human-associated fecal contamination in environmental waters without the need to run two separate qPCR assays. Despite its advantages over qPCR, the upper quantification limit of the dPCR assay with currently available instrumentation is approximately four orders of magnitude lower than that achievable by qPCR. Consequently, dilution is needed for measurement of high concentrations of target organisms such as those typically observed following sewage spills.

A Duplex Digital PCR Assay for Simultaneous Quantification of the Enterococcus spp. and the Human Fecal-associated HF183 Marker in Waters

This manuscript describes a duplex digital PCR assay that can be used to simultaneously quantify Enterococcus spp. and the HF183 genetic markers as indicators of general and human-associated fecal contamination in recreational waters.

This manuscript describes a duplex digital PCR assay (EntHF183 dPCR) for simultaneous quantification of Enterococcus spp. and the human fecal-associated ...

Protocol for Microplastics Sampling on the Sea Surface and Sample Analysis

Microplastic pollution in the marine environment is a scientific topic that has received increasing attention over the last decade. The majority of scientific publications address microplastic pollution of the sea surface. The protocol below describes the methodology for sampling, sample preparation, separation and chemical identification of microplastic particles. A manta net fixed on an &#187;A frame&#171; attached to the side of the vessel was used for sampling. Microplastic particles caught in the cod end of the net were separated from samples by visual identification and use of stereomicroscopes. Particles were analyzed for their size using an image analysis program and for their chemical structure using ATR-FTIR and micro FTIR spectroscopy. The described protocol is in line with recommendations for microplastics monitoring published by the Marine Strategy Framework Directive (MSFD) Technical Subgroup on Marine Litter. This written protocol with video guide will support the work of researchers that deal with microplastics monitoring all over the world.

The protocol below describes the methodology for: microplastics sampling on the sea surface, separation of microplastic and chemical identification of particles. This protocol is in line with the recommendations for microplastics monitoring published by the MSFD Technical Subgroup on Marine Litter.

Microplastic pollution in the marine environment is a scientific topic that has received increasing attention over the last decade. The majority of ...

Ecotoxicological Method with Marine Bacteria Vibrio anguillarum to Evaluate the Acute Toxicity of Environmental Contaminants

Bacteria are an important component of the ecosystem, and microbial community alterations can have a significant effect on biogeochemical cycling and food webs. Toxicity testing based on microorganisms are widely used because they are relatively quick, reproducible, cheap, and are not associated with ethical issues. Here, we describe an ecotoxicological method to evaluate the biological response of the marine bacterium Vibrio anguillarum. This method assesses the acute toxicity of chemical compounds, including new contaminants such as nanoparticles, as well as environmental samples. The endpoint is the reduction of bacterial culturability (i.e., the capability to replicate and form colonies) due to exposure to a toxicant. This reduction can be generally referred to as mortality. The test allows for the determination of the LC50, the concentration that causes a 50% decrease of bacteria actively replicating and forming colonies, after a 6 h exposure. The culturable bacteria are counted in terms of colony forming units (CFU), and the &#34;mortality&#34; is evaluated and compared to the control. In this work, the toxicity of copper sulphate (CuSO4) was evaluated. A clear dose-response relationship was observed, with a mean LC50 of 1.13 mg/L, after three independent tests. This protocol, compared to existing methods with microorganisms, is applicable in a wider range of salinity and has no limitations for colored/turbid samples. It uses saline solution as the exposure medium, avoiding any possible interferences of growth medium with the investigated contaminants. The LC50 calculation facilitates comparisons with other bioassays commonly applied to ecotoxicological assessments of the marine environment.

Ecotoxicological Method with Marine Bacteria Vibrio anguillarum to Evaluate the Acute Toxicity of Environmental Contaminants

This work describes a new protocol to assess the ecotoxicity of pollutants, including emerging contaminants such as nanomaterials, using the marine bacterium Vibrio anguillarum. This method allows for the determination of the LC50, or mortality, the concentration that causes a 50% decrease in bacteria culturability, after a 6 h exposure.

Bacteria are an important component of the ecosystem, and microbial community alterations can have a significant effect on biogeochemical cycling and food ...

Continuous Instream Monitoring of Nutrients and Sediment in Agricultural Watersheds

Pollutant concentrations and loads in watersheds vary considerably with time and space. Accurate and timely information on the magnitude of pollutants in water resources is a prerequisite for understanding the drivers of the pollutant loads and for making informed water resource management decisions. The commonly used &#34;grab sampling&#34; method provides the concentrations of pollutants at the time of sampling (i.e., a snapshot concentration) and may under- or overpredict the pollutant concentrations and loads. Continuous monitoring of nutrients and sediment has recently received more attention due to advances in computing, sensing technology, and storage devices. This protocol demonstrates the use of sensors, sondes, and instrumentation to continuously monitor in situ nitrate, ammonium, turbidity, pH, conductivity, temperature, and dissolved oxygen (DO) and to calculate the loads from two streams (ditches) in two agricultural watersheds. With the proper calibration, maintenance, and operation of sensors and sondes, good water quality data can be obtained by overcoming challenging conditions such as fouling and debris buildup. The method can also be used in watersheds of various sizes and characterized by agricultural, forested, and/or urban land.

With the advancement of technology and the rise in end-user expectations, the need and use of higher temporal resolution data for pollutant load estimation has increased. This protocol describes a method for continuous in situ water quality monitoring to obtain higher temporal resolution data for informed water resource management decisions.

Pollutant concentrations and loads in watersheds vary considerably with time and space. Accurate and timely information on the magnitude of pollutants in ...

The Plant Infection Test: Spray and Wound-Mediated Inoculation with the Plant Pathogen Magnaporthe Grisea

Plants possess a powerful system to defend themselves against potential threats by pathogenic fungi. For agriculturally important plants, however, current measures to combat such pathogens have proved too conservative and, thus, not sufficiently effective, and they can potentially pose environmental risks. Therefore, it is extremely necessary to identify host-resistance factors to assist in controlling plant diseases naturally through the identification of resistant germplasm, the isolation and characterization of resistance genes, and the molecular breeding of resistant cultivars. In this regard, there is need to establish an accurate, rapid, and large-scale inoculation method to breed and develop plant resistance genes. The rice blast fungal pathogen Magnaporthe grisea causes severe disease symptoms and yield losses. Recently, M. grisea has emerged as a model organism for studying the mechanisms of plant-fungal pathogen interactions. Hence, we report the development of a plant virulence test method that is specific for M. grisea. This method provides for both spray inoculation with a conidial suspension and wounding inoculation with mycelium cubes or droplets of conidial suspension. The key step of the wounding inoculation method for detached rice leaves is to make wounds on plant leaves, which avoids any interference caused by host penetration resistance. This spray/wounding protocol contributes to the rapid, accurate, and large-scale screening of the pathotypes of M. grisea isolates. This integrated and systematic plant infection method will serve as an excellent starting point for gaining a broad perspective of issues in plant pathology.

The Plant Infection Test: Spray and Wound-Mediated Inoculation with the Plant Pathogen Magnaporthe Grisea

Here, we present a protocol to test plant virulence with the plant pathogen Magnaporthe grisea. This report will contribute to the large-scale screening of the pathotypes of fungi isolates and serve as an excellent starting point for understanding the resistant mechanisms of plants during molecular breeding.

Plants possess a powerful system to defend themselves against potential threats by pathogenic fungi. For agriculturally important plants, however, current ...

Construction of a Low-cost Mobile Incubator for Field and Laboratory Use

Incubators are essential for a range of culture-based microbial methods, such as membrane filtration followed by cultivation for assessing drinking water quality. However, commercially available incubators are often costly, difficult to transport, not flexible in terms of volume, and/or poorly adapted to local field conditions where access to electricity is unreliable. The purpose of this study was to develop an adaptable, low-cost and transportable incubator that can be constructed using readily available components. The electronic core of the incubator was first developed. These components were then tested under a range of ambient temperature conditions (3.5 &#176;C - 39 &#176;C) using three types of incubator shells (polystyrene foam box, hard cooler box, and cardboard box covered with a survival blanket). The electronic core showed comparable performance to a standard laboratory incubator in terms of the time required to reach the set temperature, inner temperature stability and spatial dispersion, power consumption, and microbial growth. The incubator set-ups were also effective at moderate and low ambient temperatures (between 3.5 &#176;C and 27 &#176;C), and at high temperatures (39 &#176;C) when the incubator set temperature was higher. This incubator prototype is low-cost (&lt; 300 USD) and adaptable to a variety of materials and volumes. Its demountable structure makes it easy to transport. It can be used in both established laboratories with grid power or in remote settings powered by solar energy or a car battery. It is particularly useful as an equipment option for field laboratories in areas with limited access to resources for water quality monitoring.

This paper describes a method for building an adaptable, low-cost and transportable incubator for microbial testing of drinking water. Our design is based on widely available materials and can operate under a range of field conditions, while still offering the advantages of higher-end laboratory-based models.

Incubators are essential for a range of culture-based microbial methods, such as membrane filtration followed by cultivation for assessing drinking water ...