Jeff J. DauzatLDEQ Southeast Regional Office

New Orleans, Louisiana(504)736-7704

Jeff.dauzat@la.gov

Bonnet Carre’ Spillway Opening - 2008

Louisiana Department of Environmental Quality (LDEQ) drafted and implemented a Sampling Plan to monitor water quality in Lake Pontchartrain as a result of the opening of the Bonnet Carre’ Spillway.

The sampling plan was developed in conjunction with other

Federal and State Agencies to avoid duplication of effort.

Site 0035Pass Rigolets

Site 0109Chef Menteur Pass

LDEQ Sampling Sites

Site 0217Causeway Crossing # 6

Site 0138Causeway Crossing # 4

Site 0216Causeway Crossing # 2Bonnet Carre’

Spillway

New Orleans

Slidell

Pass Rigolets

Site 0035

Chef Menteur Pass

Site 0109

Causeway Cross-Overs

Site 0217Causeway Crossing

# 6

Site 0138Causeway Crossing

# 4Site 0216

Causeway Crossing # 2

Water Quality Parameters

• True Color

• Specific Conductance

• TDS

• TSS

• Chloride

• Sulfate

• Alkalinity

• Turbidity

• Sodium

• TP

• TOC

• COD

• BOD

• Hardness

• Ammonia-Nitrogen

• TKN

• Nitrate+Nitrite Nitrogen

• VOC’s

• bromochloromethane

• chloromethane

• vinyl chloride

• bromomethane

• chloroethane

• trichloroflouromethane

• 1,1 –dichloroethene

• methylene chloride trans 1,2-

• dichloroethene• 1,1 –dichloroethane

• chloroform

• 1,2 –dichloroethane

• 1,1,1 –trichloroethane

• carbon tetrachloride

• 1,2 –dichlroropropane

• trichloroethene

• bromodichlroromethane

• cis- 1,3 –dichlroropropene trans- 1,3-

Water Quality Parameters – VOC’s

• dichloropropene• 1,1,2 –trichloroethane 1 –chloro-2-• bromopropane• dibromochloromethane• tetrachloroethene• bromoform 1,1,2,2-• tetrachloroethane• flourobenzene• methyl-t-butyl ether• benzene• a,a,a-trifluorotoluene• toluene• chlorobenzene• ethylbenzene• 1,3- dichlorobenzene• 1,4-dichlorobenzene• 1,2-dichlorobenzene

• Time

• Date

• Sample depth (m)

• Temperature (0C)

• Conductivity (umhos/cm)

• Salinity (ppt)

• pH ( SU)

• Dissolved Oxygen (mg/L)

• % Dissolved Oxygen

Field Parameters

First sampling event on 04/11/2008:

No remarkable significance – baseline to establish background

Sample results

Second sampling event on 05/02/2008:Changes in sample results between sample events show increases in nutrients and suspended solids.

Changes in sample results between sample events show decreases in alkalinity, sulfate and conductivity.

Changes in field parameters were noted after the Bonnet Carre’ Spillway opened:

• % Dissolved Oxygen increased to super saturation levels – algae blooms.

• Conductivity reductions – fresh water.

• Salinity reductions – fresh water.

• pH elevation – algae blooms.

• Temperature fluctuations – fresh water.

• Zero Dissolved Oxygen reading at Site 0138 on 04/25/2008. WQ meter anomaly.

Summary of Findings

Questions ?