Full document / COSOC-W-86-002 - the National Sea Grant Library

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NPDES permit number, an outfall 10, and a five-digit parameter
code similar but not identical to codes used In STORET, and
special fields for monitoring type and location. For
Individual parameters, permit limitations may be stored in
terns of maximum, minimum or average amounts or concentrations.
o Measurement Data: Measurement data are keyed to NPDES permit
number, an outfall ID, parameter code, etc., and a reporting
date, usually year and month. Measurement records contain
maximum, average or minimum amounts or concentrations reported
on monthly Discharge Monitoring Reports (DMRs) by permitted
facilities.
Creation of the selected estuary data base
The PCS data of interest was extracted and loaded into a
direct-access data base using SAS software on the NCC IBM. PCS data
were loaded for Facility data, Outfall data. Permit Limitation data, and
Measurement/Violation data for the two selected estuaries ~
Narragansett Bay and Puget Sound.
Since latitude and longitude data are not part of the PCS record
file, we merged facility coordinates from another EPA system, FINDS.
FINDS contains latitude/longitude data for the ZIP code centroids of
approximately 40 percent of PCS facilities.
The following general conclusions apply to these procedures:
o For most dischargers In PCS, only data at the Facility record
level 1s available. PCS does not contain Measurement record
data for most dischargers found at the Facility record level.
o In both estuaries, a few facilities, largely the major
dischargers, account for virtually all measurements.
o Virtually all lower level records are tied to "parent" records,
indicating good quality control.
o Many important dischargers lacked latitude/longitude
coordinates 1n FINOS, and some facility coordinates in FINDS
were inaccurate.
Data manipulation, and loading estimates
Because PCS Measurement records contain no field for unit of
measure, the first step necessary In estimating pollutant loadings from
PCS data is to link the Measurement records to their corresponding Limit
Records to obtain the standard units of measure. Moreover, to
complicate the problem of estimating pollutant loadings, some
measurements are reported in terns of concentration, e.g., milligrams
per liter, and some are reported 1n terns of quantities.
To estimate pollutant loadings using the PCS data, an algorithm
consisting of several steps was developed to standardize these