**Data Quality Notes for the Lake Pontchartrain Sediment Database**

Annotations based on quality screening techniques are provided in the
qualifier field to the right of each chemical attribute column as
illustrated here. Abbreviations and codes at the beginning of a
qualifier field (for example, AG_Q) are explained below.

Ratios with zinc provide the main discriminant function for metals and
inorganic constituents. Other appropriate normalizing constituents can
be used for organic compounds (see Manheim and others, 1998). Values
exceeding the indicated ratios are regarded as anomalous. Alert level
calls attention to unusual concentration levels. It does not necessarily
imply data quality problems. High alert levels are normally due to
presence of contaminants. Low alert levels may signify sediment
mineralogy that is naturally low in trace metals, or a leachate
procedure designed to recover contaminants but not more refractory trace
elements in unpolluted sediments.

**Table B1. Codes used in quality control field of sediment database**

\[*in consolidated table as well as full database, appendixes C and D*\]

  ------------ ----------------------------------------------------------
  **Code**     **Explanation**

  \<DL         Less than detection limit. (Concentration reads \"0\"
               because the measurement fell below the detection limit).

  DV           Discriminant value (For discussion of discriminant
               functions see \"Analytical Methods and Quality Control\"
               section).

  DVS          25% of samples for this component and source show
               unresolved anomalies in discriminant values.

  HA           High Alert (see table 8 for alert levels).

  LA           Low Alert (see table 8 for alert levels).

  Leach        Leachate method was used for metal analysis. Values
               resulting from this type of analysis have valid uses but
               are not comparable to those resulting from total
               dissolution methods. See \"Discussion\" and \"Inorganic
               Chemistry\" sections for more explanation.

  LW           Source reports data on a wet-weight basis, which gives
               lower apparent values than dry-weight basis.

  mean (n =    Multiple samples were collected from the same location and
  \*)          analyzed; the value reported is the mean (n = number of
               replicates).

  ND           Not detected.

  Repl. DL     A replicate value is below detection limit (the value
               reported is the mean of the others).

  W            Warning: unresolved questions (no quality-control
               corroboration or causal relationships for anomalous data
               are available).

               **EMAP-specific quality codes**

  CH-A         Analyte was not detected (Method Detection Limit reported
               as the variable DETLIMIT)

  CH-B         Analyte detected, but below Method Detection Limit - Use
               with discretion.

  CH-C         Lab experienced minor deficiencies meeting the QC
               requirements; reliable for EMAP assessments.

  CH-I         Co-elution; matrix interference.

  CH-N         No sediment sample taken in the field.

  CH-X         Analyte not required by EMAP protocol \-- not reported
               here; may be included in other data sets.

  CH-Z         Missing concentration value because all constituent
               analytes were non-detects.
  ------------ ----------------------------------------------------------

**Table B2. Interpretive Notes**

(for consolidated table as well as full database, appendices C and D,
respectively)

+-------------+--------------------------------------------------------+
| **Meth      |                                                        |
| odologies** |                                                        |
+-------------+--------------------------------------------------------+
| Leachate    | All metal analyses reported by Demcheck and others     |
| vs. total   | (1996), Schurtz and St Pé (1984), Byrne and DeLeon     |
|             | (1986, 1987), Landrum (1994), LDEQ (1989), and Marot   |
| dissolution | and Holmes (in review) were performed by leachate      |
| analysis    | methods. Data by Flowers and Isphording (1990),        |
|             | Macauley and Summers (1998), and Sarkar (1995) were    |
|             | performed by total dissolution techniques. Aluminum,   |
|             | iron, and barium values, in particular, are much lower |
|             | when analyzed by leachate methods than those analyzed  |
|             | by total dissolution methods. Results from these two   |
|             | methods should not be combined without normalization.  |
|             | Variable water content complicates interpretation of   |
|             | data for Byrne and DeLeon (1986, 1987), and Voyksner   |
|             | (1985). See \"Discussion\" for further information.    |
+-------------+--------------------------------------------------------+
| Dry vs. wet | The following data are reported on a wet weight basis  |
| weight      | (and, therefore, will be lower by the proportion of    |
|             | water in the samples):                                 |
|             |                                                        |
|             | \- As, Hg, and Se data of Byrne and DeLeon (1986),     |
|             |                                                        |
|             | \- organics data of Ferrario and others (1985),        |
|             |                                                        |
|             | \- organics data of Schurtz and St. Pé (1984), and     |
|             |                                                        |
|             | \- the single sample of Voyksner (1985).               |
|             |                                                        |
|             | All others are on a dry weight basis.                  |
+-------------+--------------------------------------------------------+
| *           |                                                        |
| *Organics** |                                                        |
+-------------+--------------------------------------------------------+
| Organic     | There is no low alert range for organic compounds,     |
| c           | because many are not found naturally in sediments.     |
| onstituents | Toxic ranges begin at roughly 0.18 ug/g for the most   |
| and         | toxic (\"ERM\") PCB levels. Long and others (1995)     |
| toxicities  | report toxicity ranges for PAH congeners in the 0.5 to |
|             | 9.6 ug/g range, with Total PAH having much higher      |
|             | values. Total PCBs have a range in the vicinity of     |
|             | .027, and pesticides 0.005 - 0.025.                    |
|             |                                                        |
|             | The large body of information on organics found in     |
|             | Macauley and Summers (1998) was analyzed using more    |
|             | recent, high-sensitivity methods at the Texas A&M      |
|             | Geochemical and Environmental Research Group (GERG),   |
|             | which serves several Federal agency programs. These    |
|             | data showed no internal evidence of quality problems.  |
+-------------+--------------------------------------------------------+
| **I         |                                                        |
| norganics** |                                                        |
+-------------+--------------------------------------------------------+
| Ag/Zn       | Ag/Zn ratio refers to Ag/Zn x 1000. Note that data of  |
|             | Schurtz and St. Pé (1984), Demcheck and others (1996), |
|             | and Byrne and DeLeon (1986, 1987) are leachate         |
|             | analyses, which yield lower recovery than total        |
|             | dissolution methods.                                   |
+-------------+--------------------------------------------------------+
| Al          | Leachate analyses for Al are expected to yield         |
|             | significantly lower concentrations than total          |
|             | dissolution analyses used in Flowers and Isphording    |
|             | (1990), Macauley and Summers (1998), and Sarkar        |
|             | (1995).                                                |
+-------------+--------------------------------------------------------+
| As/Zn       | As/Zn ratios have particularly wide scatter. Some      |
|             | data, analyzed by leachate techniques, showed low but  |
|             | consistent ratio patterns. These are attributed to low |
|             | recovery of non-contaminant As. Data sets with         |
|             | anomalously high discriminant levels that could not be |
|             | validated are marked with \"W\".                       |
+-------------+--------------------------------------------------------+
| Cd          | A number of EPA-EMAP data fall below the low alert     |
|             | level for Cd (.04). These values may represent local   |
|             | background levels for natural, uncontaminated          |
|             | sediments. Two data sources showed anomalous Cd values |
|             | and discriminant ratios (Cd/Zn) that were not          |
|             | corroborated by other investigators' data in           |
|             | comparable areas. The entire data sets were marked     |
|             | with \"W\".                                            |
+-------------+--------------------------------------------------------+
| Cr          | Extreme, high-alert values of Cr are found only in     |
|             | Bayou Trepagnier where major metal concentrations were |
|             | discharged into the waterway from a petrochemical      |
|             | complex (see also Mo, Pb, and Zn). See \"Discussion\"  |
|             | for comments on Cr analyzed by leachate methods.       |
+-------------+--------------------------------------------------------+
| Mo          | Elevated Mo values are exclusively found in Bayou      |
|             | Trepagnier, where this metal may have been leached     |
|             | from Mo-containing stainless steels in a petrochemical |
|             | plant.                                                 |
+-------------+--------------------------------------------------------+
| Pb          | Extreme Pb values are found mainly in Bayou            |
|             | Trepagnier.                                            |
+-------------+--------------------------------------------------------+
| Zn          | Extreme Zn values are found mainly in Bayou            |
|             | Trepagnier.                                            |
+-------------+--------------------------------------------------------+
| **Sources** |                                                        |
+-------------+--------------------------------------------------------+
| Demcheck    | Metals were extracted using standard digestion method  |
| and others  | 3050 RCRA, hot acid leach. Most were then analyzed     |
| (1996)      | using Inductively Coupled Plasma (ICP) spectrometry,   |
|             | USEPA method 200.7 (Atomic Emission Spectrometry). The |
|             | exceptions are arsenic (As), selenium (Se), and        |
|             | thallium (Tl), which were analyzed using Graphite      |
|             | Furnace Atomic Absorption Spectrometry, method 200.9;  |
|             | and mercury (Hg) which was analyzed using Flameless    |
|             | (Cold Vapor) Atomic Absorption Spectrometry, USEPA     |
|             | method 245.5.                                          |
|             |                                                        |
|             | Nitrogen (nitrate, nitrite) is reported in bottom      |
|             | material (sediments) as \"mg/kg as N\" (mg/kg = ug/g). |
|             | These parameters are normally reported for water       |
|             | column data, not sediments. The specific methods are   |
|             | not reported.                                          |
+-------------+--------------------------------------------------------+
| LDEQ (1989) | Although most metals are stated to have been analyzed  |
|             | by atomic absorption graphite furnace, whether these   |
|             | refer to total metal or acid extraction is not clearly |
|             | indicated in the analytical notes (p. 23 in the LDEQ   |
|             | report).                                               |
+-------------+--------------------------------------------------------+
| Tarver and  | Coordinates for sample locations were derived from a   |
| Dugas       | sketch map with a probable error of +/- 1minute.       |
| (1973)      |                                                        |
+-------------+--------------------------------------------------------+
| Tarver and  | The sample locations were only given in generalized    |
| Savoie      | terms (grid squares drawn on a map with sides of       |
| (1976)      | approximately 3 minutes in length). The coordinates    |
|             | used in this database have been approximated by        |
|             | calculating the coordinates of the centroids of these  |
|             | grid squares. Locations for stations along the edge of |
|             | lakes are the approximated centroids of the irregular  |
|             | shape formed by the square and the shoreline.          |
+-------------+--------------------------------------------------------+

**Table B3. Station class codes used for EPA EMAP data in \"GEN_CMMNTS\"
field in sediment database**

Table B3 refers to the selection process for USEPA EMAP stations. It may
be noted that the EMAP

monitoring concept called for stations whose positions were selected in
statistically random ways,

permitting the agency to compare regional areas in a statistically
conformable way. Many of the EMAP

stations were resampled in successive years and therefore reveal spatial
variability (Macauley and

Summers, 1998).

Also, see <http://www.epa.gov/emap/html/dataI/estuary/data/> for further
information regarding the EMAP

program.

+-------------+--------------------------------------------------------+
| **Code**    | **Explanation**                                        |
+-------------+--------------------------------------------------------+
| BASE        | Stations that were randomly selected based on EMAP     |
|             | sampling design (grid).                                |
+-------------+--------------------------------------------------------+
| INDEX       | Stations that were paired with small estuary and tidal |
|             | river base sites. They were intended to represent the  |
|             | area of sediment deposition with the estuary or river. |
|             | Not random.                                            |
+-------------+--------------------------------------------------------+
| ITE         | Indicator Testing and Evaluation Sites - only for      |
|             | 1991. Selected specifically to test indicators\'       |
|             | ability to discriminate between degraded and reference |
|             | sites.                                                 |
+-------------+--------------------------------------------------------+
| SUPPL       | Stations that were randomly selected by using the EMAP |
|             | grid design and reducing it to fit within a single     |
|             | estuary.                                               |
+-------------+--------------------------------------------------------+
| QA/QC       | The replicate sampling of a base station (exact        |
|             | location) within a short time span. (Collection        |
|             | methods quality reference.)                            |
+-------------+--------------------------------------------------------+
| REP-91      | Between-year replicates of 1991 base sites. These 1991 |
|             | sites were sampled every year to represent variation   |
|             | and long term trends. (No within-year replicates, see  |
|             | next definition.)                                      |
+-------------+--------------------------------------------------------+
| REP-92      | Randomly selected sites that are \"near-by\" to one    |
|             | another to evaluate variability REP-93 within a given  |
| REP-93      | area (for example, within a hexagon or small estuary). |
|             | Used to test the REP-94 EMAP design.                   |
| REP-94      |                                                        |
+-------------+--------------------------------------------------------+
| VARIANCE    | Trend sites selected to evaluate variation and long    |
|             | term trends (selected in addition to the REP-91        |
|             | sites).                                                |
+-------------+--------------------------------------------------------+

EPA Disclaimer: \"Although the data described in this article have been
funded wholly or in part by the U.S. Environmental Protection Agency
through its EMAP Estuaries Program, it has not been subjected to

Agency review, and therefore does not necessarily reflect the views of
the Agency and no official

endorsement should be inferred.\"

**Table B4. Miscellaneous abbreviations used in sediment database**

**STATION TABLE FIELDS**

[AGNC1_SPON]{.underline}: (Agency or researcher sponsoring or publishing
the work)

-   LDEQ = Louisiana Department of Environmental Quality

-   LDEQ-OWR-WPCD = Louisiana Department of Environmental Quality -
    Office of Water Resources - Water Pollution Control Division

-   LDNR-CZMD = Louisiana Department of Natural Resources - Coastal Zone
    Management Division

-   LSU = Louisiana State University

-   UNO = University of New Orleans

-   USEPA = United States Environmental Protection Agency

-   USACE = United States Army Corps of Engineers

-   USGS = United States Geological Survey

-   USGS - WRD = United States Geological Survey - Water Resources
    Division

[SRCE_OR_REF (or COM_ON_REF)]{.underline}: (Source of information, or
reference)

Byrne, C.J., and DeLeon, I.R., 1986, Trace metal residues in biota and
sediments from Lake Pontchartrain, Louisiana: Bulletin of Environmental
Contamination and Toxicology, v. 37, p. 151-158.

Byrne, C.J., and DeLeon, I.R., 1987, Contribution of heavy metals from
municipal runoff to the sediments of Lake Pontchartrain: Chemosphere, v.
16, issue 10-12, p. 2579-2583.

Chew, D.L., and Swilley, L.J., 1987, Clam shell dredging in Lakes
Pontchartrain and Maurepas, Louisiana: Draft Environmental Impact
Statement and Appendices: U.S. Army Corps of Engineers, approx. 162 p.
plus appendixes. \[Same data as in Schurtz and St. Pé, 1984.\]

Childers, G.W., 1985, A baseline study of the water quality and selected
faunal communities in Lake Maurepas, its major tributaries, and Pass
Manchac: Hammond, LA, Southeastern Louisiana University, Department of
Biological Sciences, 330 p.

Crocker, J.A., 1988, Sediment deposition in Lake Pontchartrain from the
1973 Bonnet Carré Spillway operation: New Orleans, LA, University of New
Orleans, Department of Geology and Geophysics, M.Sc. thesis, 81 p.

Demcheck, D.K., Garrison, C.R., and McGee, B.D., 1996, Selected
water-quality data for the lower Mississippi River, Bonnet Carré
Spillway, and Lake Pontchartrain area, Louisiana, April through June
1994 and 1974-84: U.S. Geological Survey, Open-File Report 96-652-A, 125
p.

Dunbar, J.B., Blaes, M.R., Dueitt, S.E., May, J.R., 1995, Geological
investigation of the Mississippi River deltaic plain: Vicksburg, MS,
U.S. Army Corps of Engineers, Waterways Experiment Station, Technical
Report GL-84-15.

Ferrario, J.B., Lawler, G.C., DeLeon, I.R., and Laseter, J.L., 1985,
Volatile organic pollutants in biota and sediments of Lake
Pontchartrain: Bulletin of Environmental Contamination and Toxicology,
v. 34, p. 246-255.

Flocks, J.G., 1998 \[and unpub. data\], New field sampling techniques
and data description, *in* Manheim, F.T., ed., Lake Pontchartrain Basin:
Bottom sediments and regional scientific and educational resources: U.S.
Geological Survey Open-File Report 98-805, 1 CD-ROM.

Flowers, G.C., 1987, unpub. data. \[Data used in Flowers and Isphording,
1990.\]

Flowers, G.C., and Isphording, W.C., 1990, Environmental sedimentology
of the Pontchartrain Estuary: Gulf Coast Association of Geological
Societies Transactions, v. 40, p. 237-250.

Landrum, K.E., 1994 \[unpub. data\], Environmental sedimentology and
trace-metal geochemistry of the Barataria Basin and St. Bernard Delta
Estuaries, Louisiana: Draft report to the Louisiana Department of
Environmental Quality, 101 p. plus appendixes. \[See also Landrum,
1995\].

Landrum, K.E., 1995, Trace metal variability of estuarine sediments, St.
Bernard Geomorphic Region, Louisiana: Gulf Coast Association of
Geological Societies Transactions, v. 45, p. 365-370.

LDEQ, 1989, Impact assessment of Bayou Trepagnier: Baton Rouge, LA,
Louisiana Department of Environmental Quality, Office of Water
Resources, Water Pollution Control Division, 71 p. plus appendixes.

Macauley, J.M., and Summers, J.K., 1998, Environmental Monitoring
Assessment Program (EMAP) Louisiana Province Database: USEPA Office of
Research and Development, online at
<http://www.epa.gov/emap/html/dataI/estuary/data/>.

Marot, M.E., and Holmes, C.W., in review, Recent sediment distribution
in Lake Pontchartrain, Louisiana, as monitored by Beryllium-7: U.S.
Geological Survey Open-File Report 99-xxx.

McFall, J., Antoine, S.R., and DeLeon, I.R., 1985, Base-neutral
extractable organic pollutants in biota and sediments from Lake
Pontchartrain: Chemosphere, v. 14, no. 10, p. 1561-1569.

Overton, E.B., Byrne, C.J., McFall, J.A., Antoine, S.R., and Laseter,
J.L., 1984, Organic chemical and heavy metal analyses of sediment,
biota, and water from Lake Pontchartrain, Louisiana: Baton Rouge, LA,
Center for Bio-Organic Studies, University of New Orleans, 170 p.
\[Report for Louisiana Department of Natural Resources; same project as
Schurtz and St. Pé, 1984\].

Roberts, D.W., 1981, Structure and function of nearshore and open lake
benthic communities in Lake Pontchartrain, Louisiana: Baton Rouge, LA,
Louisiana State University, M.Sc. thesis.

Sarkar, S., 1995, Heavy metal transport from Bayou Trepagnier into Lake
Pontchartrain: New Orleans, LA, Tulane University, M.Sc. thesis, 25 p.

Schurtz, M.H., and St. Pé, K.M., 1984, Report on interim findings: Water
quality investigation of environmental conditions in Lake Pontchartrain:
Louisiana Department of Environmental Quality, Water Pollution Control
Division, 86 p. plus appendixes.

Sikora, W.B., and Sikora, J.P., 1982, Ecological characterization of the
benthic community of Lake Pontchartrain, Louisiana: Baton Rouge, LA,
Louisiana State University, Coastal Ecology Laboratory, Center for
Wetlands Resources, 214 p.

Tarver, J.W., and Dugas, R.J., 1973, A study of the clam, Rangia
cuneata, in Lake Pontchartrain and Lake Maurepas: Louisiana Wild Life
and Fisheries Commission; Oyster, Water Bottoms and Seafoods Division,
Technical Bulletin 5, 97 p.

Tarver, J.W., and Savoie, L.B., 1976, An inventory and study of the Lake
Pontchartrain-Lake Maurepas estuarine complex: Louisiana Wild Life and
Fisheries Commission; Oyster, Water Bottoms and Seafoods Division,
Technical Bulletin 10, 159 p.

Voyksner, R.D., 1985, Final report: Analysis of metals and organics in
sediment and biota: Research Triangle Park, NC, Research Triangle
Institute, report number RTI/2830/00-01Q, 68 p.

[PROJ_NAME]{.underline}: (Name of project when data source/study is part
of a larger study)

EMAP = Environmental Monitoring and Assessment Program

[AREA_CODE]{.underline}: (Alphabetical code corresponding to approximate
sample location)

BLaBr = Bayou LaBranche

BretS = Breton Sound

BTrep = Bayou Trepagnier

CMent = Chef Menteur

EngCa = Engineers Canal

ICW = Intracoastal Waterway

IHNC = Inner Harbor Navigation Canal

LBorg = Lake Borgne

LMaur = Lake Maurepas

LP = Lake Pontchartrain

LP-BC = Lake Pontchartrain, Bonnet Carre Region

LP-CE = Lake Pontchartrain, central region east of Causeway

LP-CW = Lake Pontchartrain, central region west of Causeway

LP-NO = Lake Pontchartrain, New Orleans region

LP-NS = Lake Pontchartrain, north shore region

LP-PH = Lake Pontchartrain, Pointe aux Herbes region

LP-RG = Lake Pontchartrain, Rigolets region

LP-WS = Lake Pontchartrain, west shore region

MissB = Mississippi Bayou

MRGO = Mississippi River Gulf Outlet\
Rigol = Rigolets

[ORIG_STATN]{.underline}: (Original name or number of station at which
sample was collected)

Each EPA EMAP sample name is a code for the station location that is 8
characters long with the following placements defined as:

Characters 1,2 - Province code - e.g. \"LA\" in LA94LR01 signifies the
Louisianian Province

Characters 3,4 - Year - e.g. \"94\" in LA94LR01 signifies 1994 sampling
year

Characters 5,6 - Class - e.g. \"LR\" in LA94LR01 signifies Large Estuary
Random class

\"SR\" in LA94SR01 signifies Small Estuary Random class

\"RR\" in LA94RR01 signifies Tidal River Random class

\"SP\" in LA94SP14 signifies Small Estuary Replicate

\"RP\" in LA94RP05 signifies Tidal River Replicate

\"LS\" in LA94LS01 signifies Large Estuary Supplement

\"IN\" in LA91IN01 signifies Indicator, Testing, and Evaluation class

\"QC\" in LA91QC11 signifies Quality Control Revisit

\"RI\" in LA91RI01 signifies Tidal River Index class

\"SI\" in LA91SI01 signifies Small Estuary Index class

\"TR\" in LA94TR01 signifies Temporal Replicate

\"TT\" in LA94TT01 signifies Temporal Replicate

\"VR\" in LA94VR01 signifies Temporal Replicate

Characters 7,8 - Station Number - e.g. \"01\" in LA94LR01 signifies
station 1 in LR class

[INIT_NTRER]{.underline}: (Initials of the person who entered the data
from the original source)

agm = Andrew G. McIntire

LH = Laura Hayes

**INORGANICS TABLE FIELDS**

[COMMENT1]{.underline}: (Any further information about analysis for all
or specific metals)

ICP-AES = Inductively Coupled Plasma - Atomic Emission Spectrometry

**GRAIN SIZE TABLE FIELDS**

[COMMENT_O]{.underline}: (further comments on grain size analysis)

Texture too coarse? = Texture values from this source tend to form a
distinct group. Sand is higher than in data from other sources or
expected from hydrologic setting.

**UNITS**

cm = centimeters

ft = feet

g = grams

in = inches

lat = latitude

long = longitude

m = meters

mg/kg = milligrams per kilogram (1 µg/g = 1 mg/kg)

ng/g = nanograms per gram (1µg/g = 1000 ng)

ppb = parts per billion (1 µg/g = 1000 ppb)

ppm = parts per million (1 µg/g = 1 ppm)

µg/g = micrograms per gram

µg/kg = micrograms per kilogram (1 µg/g = 1000 µg/kg)

**FIELD HEADINGS ENDING IN...**

C = concentration

Q = qualifier

DL or D = detection limit

**For codes and abbreviations used in any qualifier field (headings
ending in \"Q\"), see appendix B, table B1.**