Stockton Deep Water Ship Channel (DWSC)

Demonstration Dissolved Oxygen Aeration Facility

July 2009 Monthly Report

Thisreport includes monthly plots for the Stockton Deep Water Ship Channel (DWSC) Demonstration Dissolved Oxygen (DO) Aeration Facilityremote monitoring stations (Navigation Aid (NA) 40, 42, 43 and 48), handheld instrument data,California Data Exchange Center (CDEC) Rough and Ready Island (RRI) station data, and CDEC San Joaquin River at Garwood Bridge (SJG) station datafor the month of July2009. All reported data is provisional and subject to change.

Summary:

The Aeration Facility has been off since September 26, 2008. Average monthly DO levels for July 2009 were above the 5.0milligrams per liter (mg/L) December 1 through August 31 minimum water quality objective for the California Regional Water Quality Control Board (RWQCB) San Joaquin River Basin Plan.

DO concentrations at all monitoring locations stayed nearly the same compared to June 2009. The monthly average DOconcentrations ranged from approximately 5.42 mg/L at NA48 to 6.06 mg/L at NA40 for July 2009.The monthly average remote monitoring station DO concentrations were within -0.19 to 0.45 mg/L of the RRI station data. The monthly average handheld measured DO (at 12 foot depth) and the remote monitoring stations DO values were within 0.06 to 0.45 mg/L. Minimum monthly 15-minute DO concentrations were below the 5.0 mg/L minimum water quality objective at all monitoring locations with the exception of NA42. The minimum monthly DO concentrations below the water quality objective ranged from 3.72 mg/L at NA48 to 4.86 mg/L at NA40. The minimum monthly DO concentration at NA42 was 5.09 mg/L.

Theaverage monthly water temperature increased 4.1degreesFahrenheit (°F) from 74.9°F to79.0°Fcompared to June 2009

The July 2009 monthly average SJG flow was -229cubic feet per second (cfs). The monthly average SJG flow decreased 323 cfs compared to June 2009.

As observed in June, there is no sign of noticeable instrumentation drift-up/down for the July data.

Figures 1and2, and Tables 1and2below present a summary of monthly data, andillustrate some of the above discussion topics.

Figure1

Figure2

Table 1

YSI Remote Stations and RRI DO (mg/L) & Temp (oF) [Post Z-Score Test]
Jul-09
RRI* DO (mg/L) / NA40 DO (mg/L) / NA42 DO (mg/L) / NA43 DO (mg/L) / NA48 DO (mg/L) / RRI Temp (oF)
Monthly DO & Temp Averages / 5.61 / 6.06 / 5.78 / 5.67 / 5.42 / 79.0
YSI and RRI Monthly Average Difference / 0.45 / 0.16 / 0.06 / -0.19
Monthly Min DO / 4.90 / 4.86 / 5.09 / 4.30 / 3.72
Monthly Max DO / 6.50 / 7.03 / 6.43 / 6.78 / 7.02
Monthly DO STDEV / 0.36 / 0.31 / 0.21 / 0.39 / 0.54
Monthly DO Median / 5.50 / 6.05 / 5.76 / 5.69 / 5.35

*RRI DO data is from 3 foot depth. NA DO data is from 12 foot depth.

Table 2

Handheld DO Measurements @ 12 ft Depth and YSI DO Measurements Comparison
Jul-09
NA40 DO (mg/L) / NA42 DO (mg/L) / NA43 DO (mg/L) / NA48 DO (mg/L)
Handheld Monthly Averages / 5.61 / 5.62 / 5.55 / 5.36
YSI and Handheld Monthly Average Difference / 0.45 / 0.16 / 0.12 / 0.06

Additional Aeration Facility Associated Information:

DWSC Aeration Facility Operation

The Aeration Facility was briefly operated without oxygen for a routine monthly system inspection on July20, 2009.

Head of Old River Barrier Status

None

Port of Stockton Dredging Activity

None

San Joaquin River Flow Changes

None

Port of Stockton Dock 19/20 Ship Activity

None

Bay-Delta Office

DWSC July2009 Monthly ReportPage1