Andrew Eaton

Two commonly used methods for cyanotoxin analysis are enzyme‐linked immunosorbent assay (ELISA) and liquid chromatography/tandem mass spectrometry (LC–MS/MS). Two rounds of interlaboratory comparisons of ELISA and LC–MS/MS analyses were conducted with 12 participating laboratories to evaluate method performances in various matrices, including cyano...

Cyanotoxin standards are commercially available from various suppliers. To investigate the potential impact of different sources on the comparability of cyanotoxin monitoring results among different methods and studies, this study evaluated the quality of 86 cyanotoxin standards from nine vendors via enzyme‐linked immunosorbent assay and liquid chr...

Bromine and iodine species are precursors for forming disinfection byproducts in finished drinking waters. Our study incorporates spatial and temporal data to quantify concentrations of inorganic (bromide (Br-), iodide (I-), and iodate (IO3-)), organic, and total bromine (BrT) and iodine (IT) species from 286 drinking water sources and 7 wastewater...

Under the Safe Drinking Water Act, the US Environmental Protection Agency requires monitoring every five years for up to 30 unregulated contaminants under the Unregulated Contaminant Monitoring Rule (UCMR). Results include analyte concentrations and additional metadata. The third iteration of the UCMR (UCMR 3) is as unique as the first, with a vari...

Chlorate, currently included in the US Environmental Protection Agency's monitoring of unregulated contaminants and on the contaminant candidate list, could potentially receive a regulatory determination in the near future. This article, using available literature along with past and current monitoring data, assesses the presence of chlorate in dri...

The elk river spill is a call to action for all water utilities with hazardous chemicals in close proximity to their source water. Regardless of the regulations and responsibilities of state and federal regulators, water utilities have responsibilities and liabilities that should prompt action to identify possible chemical threats. All individuals...

The 1996 Safe Drinking Water Act (SDWA) amendments mandated a new process for selecting new contaminants for national drinking water regulations that included required national monitoring through the Unregulated Contaminant Monitoring Rule (UCMR) program. Two rounds of UCMR monitoring have been completed, and the third UCMR (UCMR3) is ongoing. Zero...

An evaluation of existing analytical methods used to measure contaminants of emerging concern (CECs) was performed through an interlaboratory comparison involving 25 research and commercial laboratories. Fifty-two methods were used in the single-blind study to determine method accuracy and comparability for 22 target compounds, including pharmaceut...

This chapter reviews some of the historical examples of drinking water regulations based on analysis of groups of contaminants and discusses the pros and cons that were observed in these analytical methods. The recent examples of potential for regulation based on analysis of compounds as groups, as noted above, is discussed in detail and an example...

Determining an appropriate set of indicators to show that a water supply is not impacted by wastewater is critical for watershed protection and for potable reuse projects. In 2010 the California State Water Resources Control Board (CA SWRCB) Blue Ribbon Panel issued a set of recommendations for a very short list (7) of compounds to be monitored for...

As part of its drinking water strategy, the US Environmental Protection Agency (USEPA) attempts to streamline the cost of compliance by regulating contaminants as groups with similar health effects, co‐occurrence, common analytical method(s), and common treatment or control processes. When the announcement to regulate up to 16 carcinogenic volatile...

Urban watersheds are susceptible to numerous pollutant sources and the identification of source-specific indicators can provide a beneficial tool in the identification and control of input loads, often times needed for a water body to achieve designated beneficial uses. Differentiation of wastewater flows from other urban wet weather flows is neede...

To evaluate laboratory performance for radionuclide analyses, a blind study of radium-226 (Ra-226), radium-228 (Ra- 228), and gross alpha and beta activity was conducted, examining five multistate certified laboratories. Although Ra-226 and gross beta measurements appeared to be accurate and precise even at low levels, measurements of Ra-228 and gr...

The presence of hexavalent chromium in drinking water isn't new, but recent media attention and pending regulations have left utilities with unanswered questions. After the Environmental Working Group (EWG) reported the presence of hexavalent chromium ‐ also called chromium 6 and Cr+6 ‐ in 35 U.S. cities, the U.S. Environmental Protection Agency (U...

Hydrazine, as a potential chloramination disinfection byproduct with a 10-6 cancer risk level of 10 ng/L, is in need of a high-performance analytical method for precise and accurate monitoring at trace levels in drinking water. The conventional procedures for hydrazine determination are arduous with off-line extraction and concentration steps and a...

The choice of wastewater compliance methods used in the United States has been largely prescribed; however, in some cases, this has led to data of unknown or poor quality. This problem is further compounded by the relatively slow regulatory approval process to incorporate discharge-specific method modifications or flexibility to using alternate, po...

EPA Methods such as 524.2 and 525.2 have specified preservation and holding time conditions for compliance monitoring, but there are clear inconsistencies between various analytical method specifications. When shipping from outside the conterminous USA, there are difficulties in either maintaining sample temperatures during shipment or regulatory c...

Under the Disinfection/Disinfection Byproducts Rule, the MCL for bromate is 10 ug/L. Method 300.1 (IC with conductivity) was promulgated in the 1990s for bromate analysis and was the only available method at the time of promulgation of Stage 1. With Stage 2, options for bromate analysis increased to include method 317, method 326, and method 321.8,...

For the drinking water supply community, one of the more problematic issues associated with chemical monitoring under the Safe Drinking Water Act (SDWA) is the establishment of meaningful reporting limits. Historically, reporting limits have been poorly defined by the regulations and have been set arbitrarily and inconsistently. To address this iss...

It is often desirable to quantify both dissolved Cr(VI) and total Cr in samples accurately. Various protocols are now being utilized to quantify the amount of total chromium in natural waters and each of these has possible interferences. This study describes the shortcomings of each method when particulate iron is present in a water sample, and a m...

Regulatory monitoring methods are currently prescribed, by in large, by USEPA. A performance-based approach to methods has been suggested as a better means for ensuring improved water information in a variety of monitoring programs in the U.S. One obstacle to implementing a performance-based approach is identifying laboratory requirements that veri...

Perchlorate (ClO4−) has emerged in recent years to become a significant new threat to drinking water supplies and the environment. It is an oxidizing anion that originates as contaminant in the environment from the dissolution of ammonium, potassium, magnesium, or sodium salts. Perchlorate is very mobile in aqueous systems and can persist for many...

A modified field technique can quantify particulate As, soluble As(III), and soluble As(V) in drinking water. Several problems with commonly used techniques that analyze for arsenic are reported, and solutions are proposed. Analytical techniques can accurately detect <0.5 μg/L total arsenic if certain conditions are met: iron, nitrate, and other in...

Several problems with commonly used techniques that analyze for arsenic are reported, and solutions are proposed. Analytical techniques can accurately detect <0.5 {micro}g/L total arsenic if certain conditions are met: iron, nitrate, and other interferences are overcome in hydride generation techniques, poor recoveries are overcome in graphite furn...

Several problems with commonly used techniques that analyze for arsenic are reported, and solutions are proposed. Analytical techniques can accurately detect <0.5 μg/L total arsenic if certain conditions are met: iron, nitrate, and other interferences are overcome in hydride generation techniques, poor recoveries are overcome in graphite furnace at...

A quantitation level is proposed that should be quantifiable by a majority of laboratories. The authors describe an approach for calculating quantitation levels (QLs) that does not require changes in current laboratory practices. The reliable detection level (RDL), when defined as twice the concentration of the method detection limit (MDL), provide...

Laboratories using current, approved analytical methods can quantify arsenic in drinking water as low as 4 μg/L. In light of the fact that the maximum contaminant level (MCL) for arsenic is likely to be lowered significantly, the purpose of this study was to assess the capabilities of laboratories for arsenic analysis by atomic absorption spectrome...

With today's regulatory and staff pressures, an increasing number of water utilities are considering the use of an outside contract laboratory for all or part of their analytical needs. This article is intended as a guide for utilities in selecting a contract laboratory to best serve their requirements. Among the desirable qualities sought in an ou...

A study of the problems encountered in nephelometric determinations of suspended sediment loads in the Chesapeake Bay estuary has led to development of a technique which uses nephelometer readings as a guide for sampling at vertical profiles in an estuary. This permits optimum sampling for concentration profiles and allows one to use nephelometer/l...

‘ Soluble’ iron levels in the Potomac River estuary are extremely low, usually less than 0·5 μm at mile 90 (freshwater) and decrease downstream to less than 0·05 μm prior to the intrusion of salt water. Removal of ‘soluble’ and fine filterable iron in the freshwater obeys first order kinetics with a rate constant of about o.1 day−1. Addition of bac...

Particulate material from the Susquehanna River is enriched in Fe (5–7%),allowing it to be distinguished from other sources of particles in surface waters of the Chesapeake Bay. Although the turbidity maximum removes most of the river-borne detritus, chemical composition of particles (SPM) indicates that Susquehanna River materials dominate the ino...

At discharges of 300-400 m 3/s, surface waters of the San Francisco Bay estuary contain dissolved Cu and Ni at levels of 1 to 4 ppb. This is approximately an order of magnitude higher than waters outside the Bay. Zn concentrations are 2-6 ppb within the estuary and generally less than 1 ppb outside. Cd concentrations are 0.08 to 0.2 ppb within the...

Release of Mn into bottom waters of the Chesapeake Bay occurs in massive quantities during summertime periods of anoxia. The measured flux is much greater than can be accounted for by diffusion from pore waters under normal concentration gradients and is enhanced by dissolution of Mn-oxides under low Eh conditions. Extrapolating flux rates to the a...

Glass support frits for 47-mm Millipore filter holders rapidly adsorb up to 600 nmol of ammonium from fresh or brackish waters (salinity < 5%). Certain glass-fiber filters may also adsorb at least 200 nmol of ammonium. The adsorbed ammonium is released on contact with higher salinity or high K/sup +/ waters. Distilled deionized water is not an effe...

Geographic variations of leachable Fe, Mn, Cu, Zn, Co, and Ni in San Francisco Bay sediments indicate that Fe, Mn, Co, and Ni are all predominantly supplied to bay sediments from the San Joaquin-Sacramento River system, with little evidence for direct contributions from municipal and industrial sources. In contrast, both Cu and Zn have significant...

A detailed study of particulate and dissolved cadmium distributions on 83 seawater samples from six profiles in the open North Atlantic Ocean showed a relatively homogenous distribution. The mean concentration of cadmium was 60 ± 27 ng/kg and the median concentration of particulate cadmium was 0.2 ng/kg. Although there are regional differences in d...

This report describes the methods and results of a study of copper cycling in the Patuxent River estuary. The study focused on detailed sampling of the water column over a number of seasons to determine: (1) the amount of excess copper in the estuary which may be attributable to corrosion of condenser tubes at the Chalk Point Power Plant; (2) the g...