United States
Environmental Protection
Agency
National Exposure
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/SR-96/049 May 1996
4>EPA Project Summary
Analysis of Acid Precipitation
Samples Collected by State
Agengies—Sampling Period
January 1993-December 1993
Lloyd S. Shepard
This report presents analytical data
from the 29 acid precipitation collec-
tion sites in the State-Operated Net-
work that were operational in 1993.
Samples are collected weekly in plas-
tic bag liners and shipped in 500 mL
polyethylene bottles to Global
Geochemistry Corporation (the central
laboratory for the network). This report
contains maps showing the location of
each site, plots of analytical data, tables
of all field and analytical data, plots
comparing field and laboratory pH and
conductivity, and information on data
quality. Samples are analyzed for pH,
strong acid, conductivity, fluoride, chlo-
ride, nitrite, phosphate, bromide, nitrate,
sulfate, ammonium, sodium, potassium,
calcium, and magnesium. The central
laboratory renders technical assistance
to the collection sites on problems con-
cerning pH and conductivity. Each of
the ten participating state agencies re-
ceives analytical reports for the
samples analyzed the previous month.
Analyte concentration data are put on
tape for later inclusion in a national
acid deposition data base.
This Project Summary was developed
by EPA's National Exposure Research
Laboratory, Research Triangle Park, NC,
to announce key findings of the re-
search project that is fully documented
in a separate report of the same title
(see Project Report ordering informa-
tion at back).
Introduction
The main report presents analytical data
from the 29 acid precipitation collection
sites in the State-Operated Network for
the year 1993. Samples are collected
weekly in plastic bags inserted in buckets
and shipped in 500 mL polyethylene bottles
to Global Geochemistry Corporation (the
central laboratory for the network). Global
Geochemistry analyzes the samples and
monthly sends a report of the analytical
results to each site. Global Geochemistry
also summarizes these results on mag-
netic tape for inclusion in a national acid
deposition data base. Individuals con-
cerned with the collection and interpreta-
tion of acid precipitation sample results
will find this report of interest.
Overview of Network Operation
and Sample Analysis
The central laboratory analyzes weekly
acid precipitation samples for pH, strong
acid, conductivity, fluoride, chloride, bro-
mide, nitrate, nitrite, sulfate, phosphate,
ammonium, sodium, potassium, calcium,
and magnesium. The methods indicated
in Table I are used for these analytes.
The State-Operated Network collects
weekly samples using a wet/dry bucket
collector. Samples are collected in a plas-
tic bag inserted in the bucket; an aliquot
of the collected sample is sent to the
central laboratory in a 500 mL polyethyl-
ene bottle at ambient temperature (except
for one site that ships samples in a cooler).
The locations of the network sites are
shown in Figure 1.
The central laboratory provides plastic
bucket liners, 500 mL sample bottles, field
data sheets, pH and conductivity solu-
tions, and other supplies incidental to col-
lecting and shipping a collected rain
sample. The central laboratory also pro-
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Table 1. Method Used for Selected Analytes
Analyte Analytical Method
Methodology
pH
Conductivity
Acidity
Cl, P04, S04
N03, F, Br, N02
NH4
A/a, K, Ca, Mg
EPA Method 150.1
EPA Method 120.1
Gran Titration
EPA Method 300. 0
EPA Method 350.1
EPA Methods 273. 1,
258.1,215.1,242.1
pH Electrode
Conductivity
Titration
Ion Chromatograph
Colorimetric
Atomic absorption
for Ca, Mg, Flame
Emission for A/a, K
vides technical assistance whenever it is
requested by a field site. This assistance
consists mostly of field pH and conductiv-
ity measurement procedures and equip-
ment.
Monthly, the central laboratory sends a
report to each state agency describing the
analytical results for all samples analyzed
from that agency's sites for the last month.
The central laboratory also summarizes
the analytical results for all the sites on
magnetic tape.
Report Contents
The report contains a table showing the
latitude and longitude of each of the sites.
It also contains plots of analytical data for
each site during the time period, tables of
all field and analytical data, a comparison
of analyte concentrations at all sites (fre-
quency of occurrence), precipitation
weighted data for each site, plots compar-
ing field and laboratory pH and conductiv-
ity, and quality control tables and plots.
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Lloyd S. Shepardis with Global Geochemistry Corporation, Canoga ParkCA 91303.
Berne I. Bennett is the EPA Project Officer (see below).
The complete report, entitled "Analysis of Acid Precipitation Samples Collected by
State Agengies—Sampling Period January 1993-December 1993," (Order No.
PB96-175245; Cost: $44.00, subject to change) will be available only from
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at
National Exposure Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection Agency
National Risk Management
Research Laboratory (G-72)
Cincinnati, OH 45268
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
Official Business
Penalty for Private Use
$300
EPA/600/SR-96/049
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