1、Designation: D6146 97 (Reapproved 2012)Standard Guide forMonitoring Aqueous Nutrients in Watersheds1This standard is issued under the fixed designation D6146; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revisio
2、n. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONVarious forms of nitrogen and phosphorus are plant nutrients, both naturally occurring andmanmade, that can threaten water resourc
3、es. Nutrients that run off or infiltrate through the soil profilecan result in unfishable and unswimmable streams, lakes, and estuaries, and unsafe surface and groundwater used for drinking. High concentrations of nitrate in drinking water are a threat to young infants,and surface waters can suffer
4、from algal blooms, fish kills, and unpalatable and unsafe water forswimming and drinking. Nutrients are also added to watersheds via chemigation.This guide recommends a process for developing and implementing monitoring projects fornutrients in a watershed. It follows Guide D5851 with more specifics
5、 applicable to watersheds andnutrients. These guidelines are presented for use in the nationwide strategy for monitoring developedby the Intergovernmental Task Force on Monitoring (ITFM). The nationwide monitoring strategy isan effort to improve the technical aspects of water monitoring to support s
6、ound water qualitydecision-making. It is needed to integrate monitoring activities more effectively and economically toachieve a better return of investments in monitoring projects (1).2Guide D6145 is offered as a guide for monitoring actual and potential nonpoint and point sourcepollution within a
7、watershed. The guide is applicable to surface water and ground water resources,recognizing the need for a comprehensive understanding of naturally occurring and manmade impactsto the entire watershed hydrologic system.1. Scope1.1 PurposeThis guide is intended to provide generalguidance on a watershe
8、d monitoring program directed towardthe plant nutrients nitrogen and phosphorus. The guide offers aseries of general steps without setting forth a specific course ofaction. It gives assistance for developing a monitoring programbut not a program for implementing measures to improve waterquality.1.2
9、This guide applies to waters found in streams and rivers;lakes, ponds, and reservoirs; estuaries; wetlands; the atmo-sphere; and the vadose and subsurface saturated zones (includ-ing aquifers). This guide does not apply to nutrients found insoils, plants, or animals.1.3 Nutrients as used in this gui
10、de are intended to includenitrogen and phosphorus in dissolved, gaseous, and particulateforms. Specific species of nitrogen include: nitrate, nitrite,ammonia, organic, total Kjeldahl, and nitrous oxide. Thespecies of phosphorus include total, total dissolved, organic,acid-hydrolyzable, and reactive
11、phosphorus as described in (2)1.4 SafetyHealth and safety practices developed for aproject may need to consider the following:1.4.1 During the construction of sampling stations:1.4.1.1 Drilling practices during monitoring well installa-tions,1.4.1.2 Overhead and underground utilities during monitor-
12、ing well drilling,1.4.1.3 Traffic patterns/concerns during sampling stationinstallation,1.4.1.4 Traffic patterns/concerns during surveying samplingstation locations and elevations,1.4.1.5 Drilling through materials highly contaminated withfertilizers, and1.4.1.6 Installing monitoring equipment below
13、 the soil sur-face.1.4.2 During the collection of water samples:1This guide is under the jurisdiction of ASTM Committee D19 on Water and isthe direct responsibility of Subcommittee D19.02 on Quality Systems, Specification,and Statistics.Current edition approved June 15, 2012. Published June 2012. Or
14、iginallyapproved in 1997. Last previous edition approved in 2007 as D6146 97 (2007).DOI: 10.1520/D6146-97R12.2The boldface numbers given in parentheses refer to a list of references at theend of this standard.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19
15、428-2959, United States.1.4.2.1 Using acids for sample preservation,1.4.2.2 Sampling during flooding events and ice conditions,1.4.2.3 Traffic on bridges,1.4.2.4 Condition of sampling stations following floodevents,1.4.2.5 Sampling of water or soils, or both, highly contami-nated with fertilizers,1.
16、4.2.6 Conditions of sampling stations resulting from van-dalism,1.4.2.7 Adverse weather conditions, and1.4.2.8 Transporting liquid samples.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to
17、 establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:3D515 Test Methods for Phosphorus in Water4D653 Terminology Relating to Soil, Rock, and ContainedFluidsD1129 Terminology Relating to W
18、aterD1357 Practice for Planning the Sampling of the AmbientAtmosphereD1426 Test Methods for Ammonia Nitrogen In WaterD1739 Test Method for Collection and Measurement ofDustfall (Settleable Particulate Matter)D3370 Practices for Sampling Water from Closed ConduitsD3590 Test Methods for Total Kjeldahl
19、 Nitrogen in WaterD3856 Guide for Management Systems in LaboratoriesEngaged in Analysis of WaterD3858 Test Method for Open-Channel Flow Measurementof Water by Velocity-Area MethodD3867 Test Methods for Nitrite-Nitrate in WaterD4410 Terminology for Fluvial SedimentD4448 Guide for Sampling Ground-Wate
20、r MonitoringWellsD4696 Guide for Pore-Liquid Sampling from the VadoseZoneD4700 Guide for Soil Sampling from the Vadose ZoneD5092 Practice for Design and Installation of Ground WaterMonitoring WellsD6145 Guide for Monitoring Sediment in WatershedsD5851 Guide for Planning and Implementing a WaterMonit
21、oring Program3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this guide, refer toTerminology D1129 and Guide D5851.3.2 Definitions of Terms Specific to This Standard:3.2.1 aquifera geologic formation containing water, usu-ally able to yield appreciable water.3.2.2 ground waterth
22、at part of the subsurface water that isthe saturated zone. (D653, D18)3.2.3 nonpoint pollutiona condition of water within awater body caused by the presence of undesirable materialsfrom diffuse locations with no particular point of origin.3.2.4 vandose zonethe zone of soil located between thesurface
23、 and the water table that is not saturated.3.2.5 watershedall lands enclosed by a continuous hydro-logic surface drainage divide and lying upslope from a speci-fied point on a stream. (D4410, D19)4. Significance and Use4.1 The user of this guide is not assumed to be a trainedtechnical practitioner i
24、n the water quality field. The guide is anassembly of the components common to all aspect of water-shed nutrient monitoring and fulfills a need in the developmentof a common framework for a better coordinated and a moreunified approach to nutrient monitoring in watersheds.4.2 LimitationsThis guide d
25、oes not establish a standardprocedure to follow in all situations and it does not cover thedetail necessary to meet all of the needs of a particularmonitoring objective. Other standards and guides included inthe references describe the detail of the procedures.5. Monitoring Components5.1 A watershed
26、 monitoring program of nutrients is com-prised of a series of steps designed to collect nutrient data toachieve a stated objective. The purposes of monitoring may beseveral and include: analyzing trends, studying the fate andtransport of nutrients, defining critical areas, assessing compli-ance, mea
27、suring the effectiveness of management practices,testing for sufficient levels, making wasteload allocations,testing models, defining a water quality problem, and conduct-ing research (3).5.1.1 Monitoring to analyze trends is used to determine howwater quality is changing over time. In some cases ba
28、selinemonitoring is included as the early stage of trend monitoring.5.1.2 Fate and transport monitoring is conducted to deter-mine whether pollutants move and where they may go.5.1.3 Water quality monitoring can be used to locate criticalareas within watersheds exhibiting greater pollution loadingth
29、an other areas.5.1.4 Nutrient monitoring may also be used to assesscompliance with water quality plans or standards.5.1.5 Nutrient monitoring may assess the effectiveness ofindividual management practices in improving water qualityor, in some cases, may be used to evaluate the effect of anentire nut
30、rient management program in a watershed.5.1.6 The testing of nutrient levels in water bodies may beused to see if sufficient amounts are present to support certainaquatic organisms.5.1.7 Monitoring of receiving water bodies may be used todetermine wasteload allocations between point and nonpointsour
31、ces. Such allocations require a thorough knowledge of theindividual contributions from each source.5.1.8 Nutrient monitoring may be used to fit, calibrate, ortest a model for local conditions.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at ser
32、viceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Withdrawn.D6146 97 (2012)25.1.9 Nutrient monitoring may be used for research ques-tions such as the accuracy of different types of samplers incollecting a representativ
33、e sample.5.1.10 Finally, nutrient monitoring may be used to giveadequate definition to a water quality problem or determinewhether a problem exists. Guide for Planning D5851 providesoverall guidance on water monitoring.5.1.11 This guide suggests and discusses the following stepsin designing a waters
34、hed monitoring program for nutrients.More detail on each step may be found in (3).5.2 Step 1: Water Quality NeedThe first step is to definethe need for nutrient monitoring. The need statement shouldinclude several components: the potential or real water qualityissue requiring attention (for example,
35、 eutrophication), thepotential water resource use impairment (for example, recre-ation), the name of the actual water resource (for example,Long Lake), the potential threats or causes (for example,phosphorus), and the potential sources that may cause aproblem (for example, agriculture) (3). Very oft
36、en the need isto identify a water quality problem, but in some cases, the needmay be to assess the existing water quality whether a problemexists or not. An example of a need statement might be: “Thelack of recreation in Long Lake is due to excessive eutrophi-cation caused by excessive phosphorus lo
37、ading possibly fromagricultural sources.”5.3 Step 2: ObjectivesThe second step in developing anutrient monitoring program is to define the monitoring objec-tives. The objectives of the monitoring study should addressthe water quality need or problem. An objective statementshould include an infinitiv
38、e verb, an object word or phrase, andsome limits on the objective such as the surface or groundwater resource or watershed boundaries and variables tomonitor. An example of a monitoring objective might be: “Todetermine the effect of implementing agricultural managementpractices on phosphorus concent
39、rations in Long Lake.” Whenseveral objectives are used, a hierarchial approach may be usedto determine higher priority objectives. An objective tree canbe used to distinguish among several objectives. To determinehow several objectives can be linked, the following questioncan be asked: “Does the ach
40、ievement of objective A contributedirectly to the achievement of objective B?” If it does thenobjective A feeds into objective B and a diagram can be builtshowing all possible objectives and their linkages.5.3.1 To assess whether objectives are being achieved,objective attributes could be determined
41、. Attributes define thelevel of achievement for each objective. They answer thequestion of how close are we to achieving our goals? Forexample, are we 50 % of the way to achievement? Theseattributes for nutrient monitoring objectives are often binary;that is, either the objective is accomplished or
42、not.5.4 Step 3: Statistical DesignA statistical experimentaldesign should be stated that is consistent with the objectives ofthe monitoring program. Appropriate experimental designscould include: reconnaissance, plot, single watershed, above-and-below, two watersheds, paired watershed, multiple wate
43、r-sheds, and trend stations (3). The design selected will dictatemost other aspects of the monitoring project including thestudy scale, the number of sampling locations, the samplingfrequency, and the station type.5.4.1 Reconnaissance or synoptic designs may be used as apreliminary survey where no d
44、ata exist or to assess themagnitude and extent of a problem. This type of samplingcould be used to identify critical areas as well. A critical areais one that is contributing a significant amount of nutrients tothe water body of interest. Randomization in sampling loca-tions may be important for rec
45、onnaissance monitoring. Recon-naissance monitoring could be used in a “whole aquifer” studywith well placement located randomly or on a grid basis.5.4.2 Plot designs have been commonly used in agriculturalexperiments for 100 years (4). Plots are generally small areasthat can be replicated on the lan
46、d or waterscape. Plots allowreplication and control of certain variables, such as soil type.Plot designs are analyzed using Analysis of Variance (3).5.4.3 The single watershed before-and-after approach hasbeen sometimes used to compare water quality conditionsbefore a watershed treatment to after. G
47、enerally, this techniqueis not recommended, since the results are confounded withtime and climate variables, and should be avoided. Forexample, the water quality differences from year-to-year maybe caused by climate differences not the watershed activity.5.4.4 The above-and-below design is used afte
48、r a watershedpractice is in place. Sampling is conducted both upstream anddownstream, or in the case of ground water monitoring,up-gradient and down-gradient from the activity of interest.Although this design is not as susceptible to the effect ofclimate as the single watershed design, the differenc
49、es in waterquality between the two stations may be partly due to inherentwatershed differences such as soils or geology. If monitoring isconducted before and after the practice in installed, the designwould follow the paired watershed approach described below.5.4.5 Ground water monitoring using this approach is re-ferred to as up-gradient versus down-gradient monitoring. Thisis probably the most commonly used strategy in ground waterstudies and is appropriate for most designs. Placement of thewells is important because ground water sites are threedimensional. Gradients may
