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Capsule and disk filters are disposable, self-contained units composed of a pleated or woven filter medium encased in a polypropylene or other plastic housing that can be connected inline to a sample-delivery system (such as a submersible or peristaltic pump) that generates sufficient pressure (positive or negative) to force water...

The mission of the Water Resources Discipline of the U.S. Geological Survey (USGS) is to provide the information and understanding needed for wise management of the Nation's water resources. Inherent in this mission is the responsibility to collect data that accurately describe the physical, chemical, and biological attributes of water...

The National Field Manual for the Collection of Water-Quality Data (National Field Manual) describes protocols and provides guidelines for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. This chapter of the manual addresses the selection of equipment commonly...

Fecal indicator bacteria are used to assess the microbiological quality of water because, although not typically disease causing, they are correlated with the presence of several waterborne disease-causing organisms. The concentration of indicator bacteria is a measure of water safety for body-contact recreation or for consumption. This report provides information...

The miniaturization of sensors and other technological advances in electronics have resulted in water-quality instruments that house multiple sensors capable of simultaneous readings for various field measurements in environmental waters. With the use of these multiparameter instruments, field measurements can be determined with considerable reduction in the field work that...

Alkalinity (determined on a filtered sample) and Acid Neutralizing Capacity (ANC) (determined on a whole-water sample) are measures of the ability of a water sample to neutralize strong acid. Alkalinity and ANC provide information on the suitability of water for uses such as irrigation, determining the efficiency of wastewater processes,...

Measurement of pH is critical to the understanding of the viability and vulnerability of environmental waters and is considered a master variable in determining the aqueous geochemistry of an aqueous system. pH is a measure that represents the hydrogen-ion concentration (activity) of a solution. This section of the National Field...

Cyanobacteria (also referred to as blue-green algae) cause a multitude of water-quality concerns, including the potential to produce toxins and taste-and-odor compounds. Toxins and taste-and-odor compounds may cause significant economic and public health concerns, and are of particular interest in lakes, reservoirs, and rivers that are used for drinking-water supply,...

This report summarizes information, guidelines, and minimum requirements that apply generally to the seven field-measurement sections that comprise the rest of Chapter A6 of this U.S. Geological Survey (USGS) National Field Manual for the Collection of Water-Quality Data (NFM). Protocols are specified for establishing and maintaining data records, use of...

The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. This chapter of the manual includes procedures for the (1) determination...

The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. Chapter A6 presents procedures and guidelines for the collection of data...

Indicators of algal biomass are used to assess water quality in both moving (lotic) and stillwater (lentic) ecosystems. Algal biomass in a water body can be estimated in three ways: (1) by quantifying chlorophyll a (CHL a), (2) by measuring carbon biomass as ash-free dry mass (AFDM), or (3)...

Accurate data for the concentration of dissolved oxygen in surface and ground waters are essential for documenting changes in environmental water resources that result from natural phenomena and human activities. Dissolved oxygen is necessary in aquatic systems for the survival and growth of many aquatic organisms and is used as...

Accurate temperature measurements are required for accurate determinations of important environmental parameters such as pH, specific electrical conductance, and dissolved oxygen, and to the determination of chemical reaction rates and equilibria, biological activity, and physical fluid properties. This section of the National Field Manual (NFM) describes U.S. Geological Survey (USGS)...

The National Field Manual for the Collection of Water-Quality Data (National Field Manual) describes protocols and provides guidelines for U.S. Geological Survey (USGS) personnel who collect data that are used to assess the quality of the Nation's surface-water and ground-water resources. This chapter addresses preparations and appropriate methods for the...

Electrical conductance is a measure of the capacity of a substance to conduct an electrical current. The specific electrical conductance (conductivity) of water is a function of the types and quantities of dissolved substances it contains, normalized to a unit length and unit cross section at a specified temperature. This...

Turbidity is one of the indicators used to assess the environmental health of water bodies. Turbidity is caused by the presence of suspended and dissolved matter, such as clay, silt, finely divided organic matter, plankton and other microscopic organisms, organic acids, and dyes. This section of the National Field Manual...

Two sample-processing methods (field speciation and laboratory speciation) used at the USGS National Water Quality Laboratory (NWQL) are specific to sample analysis by inductively coupled plasma-mass spectrometry (ICP-MS) for determining the concentration of inorganic and organic arsenic species in a water sample. The field-speciation method requires NWQL Schedule 1729. The...

Reduction-oxidation (redox) potential--also referred to as Eh--is a measure of the equilibrium potential, relative to the standard hydrogen electrode, developed at the interface between a noble metal electrode and an aqueous solution containing electroactive chemical species. Measurements of Eh are used to evaluate geochemical speciation models, and Eh data can...

The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation’s surface-water and ground-water resources. This chapter addresses field-trip preparations, including selection of sample-collection sites for...

Collecting and processing water samples for analysis of mercury at a low (subnanogram per liter) level requires use of ultratrace-level techniques for equipment cleaning, sample collection, and sample processing. Established techniques and associated quality-assurance (QA) procedures for the collection and processing of water samples for trace-element analysis at the part-per-billion...

Submersible pressure transducers, developed in the early 1960s, have made the collection of water-level and pressure data much more convenient than former methods. Submersible pressure transducers, when combined with electronic data recorders have made it possible to collect continuous or nearly continuous water-level or pressure data from wells, piezometers, soil-moisture...

The National Field Manual for the Collection of Water-Quality Data (National Field Manual) describes protocols and provides guidelines for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. Chapter A3 describes procedures for cleaning the equipment used to collect...

Protozoan pathogens are widely distributed in the aquatic environment. Cryptosporidium and Giardia are the principal protozoan pathogens that are known to affect the acceptability of water supplies for public use within the United States. A sampling program for protozoan pathogens should be conducted over an extended period of time because...

More than 100 types of human pathogenic viruses may be present in fecal-contaminated waters. Coliphages are used as indicators of virus-related fecal contamination and of the microbiological quality of waters. This report provides information on the equipment, sampling protocols, and laboratory methods that are in standard use by U.S. Geological...