Continuous Diurnal D. O. Water Monitoring. Water Monitoring and Standards Bureau of Freshwater and Biological Monitoring

Transcription

1 Continuous Diurnal D. O. Water Monitoring Water Monitoring and Standards Bureau of Freshwater and Biological Monitoring

2 Objective: Develop an ambient surface water dissolved oxygen concentration database Define critical surface water dissolved oxygen concentrations in a variety of NJ streams through continuous water monitoring Develop a record of daily high and low D.O. concentrations Ambient stream dissolved oxygen concentrations have a diurnal component. Fluctuations in the range of 2-3 ppm (2-3 mg/l), during a 24 hour cycle are not uncommon In stream photosynthesis causes highest D.O. readings to occur in the late afternoon while lowest D.O. readings occurs just prior to daybreak Routine ambient monitoring collected between , would not generally record either the daily high or daily low D.O. concentrations NJ has specific water quality standards for low D.O. in FW2-NT, FW2-TM and FW2-TP waters; relying solely on grab sample (snapshot) monitoring data creates some uncertainty Continual recording of D.O. concentrations addresses this uncertainty

3 Surface Water Quality Standard Dissolved Oxygen 06/16/08 1. Not less than 7.0 mg/l at any time 1. FW2-TP hour average not less than 6.0 mg/l. Not less than 5.0 at any time 1. FW2-TM hour average not less than 5.0 mg/l, but not less than 4.0 at any time FW2-NT (except as in 4 below), SE Not less than 4.0 at any time; 1. Tidal portions of FW2-NT tributaries to the Delaware River, between Rancocas Creek and Big Timber Creek inclusive. 5. Not less than 5.0 at any time; SC Not less than 4.0 at any time; SE2 Not less than 3.0 mg/l at any time SE3 Supersaturated dissolved oxygen values shall be expressed as their corresponding 100 percent saturation values for purposes of calculating 24 hour averages 1. FW2-TM, FW2-NT, SE1

4 ph pcond( ms/cm) DO%(%) DO Conc( mg/l) Temp( C) Yards Creek near Yards Creek Reservoir typical diurnal cycle YARDSB.DAT : :24 10:18 10:12 10:06 10: : :24 10:18 10:12 10:06 10: : :24 10:18 10:12 10:06 10: : :24 10:18 10:12 10:06 10: :30 10:24 10:18 10:12 10:06 10:00 07/02/08 07/03/08 07/04/08 07/05/08 07/06/08 07/07/08 DateTime(M/D/Y)

5 Monitoring Design Automated monitoring/recording equipment will be deployed in various streams: Dissolved oxygen, dissolved oxygen saturation. water temperature, specific conductance and ph are recorded every 30 minutes for 72 hours Monitoring is conducted during June, July, August and early September based on availability of personnel Low D.O. conditions are exacerbated by hot summer temperatures and low flow conditions

6 Monitoring Design (con t) Candidate Monitoring Locations Ambient monitoring stations that have a history of low D.O. or high % D.O. saturation Impaired biological ratings Waterbodies involved in the TMDL process Recording meters will be located in free flowing sections of the stream monitored, avoiding backwaters and impounded waters Bureau of Environmental Analysis and Restoration (BEAR) and the Bureau of Water Quality Standards and Assessment (BWQSA) annually recommend sites for D.O. monitoring

7 Current Monitoring Requirements Each monitoring site will be scheduled for three (3) 72 hour monitoring events Monitoring will occur during periods of stable flow Avoid rainfall events Turbidity measurements at deployment and at retrieval of the recording meters. Phytoplankton (Chl a) samples collected at each deployment (Center of flow grab samples) Visual assessments of macrophytes and other aquatic plants using DEP s Stream Visual Assessment form

8 Data Quality Requirements To verify data quality Meters will be calibrated within 24 hours of deployment Duplicate D.O. measurements are made at the time of meter deployment and meter retrieval with a second meter that is calibrated on site Comparative D.O. readings not within the stated accuracy of the meters used will be reviewed against any available historical data from that site as an additional quality review step Data outside the stated accuracy of the meters used in the comparative readings and outside the historical range for D.O. at that site will not be used

9 Data Management/Data Availability Summarized data is stored in EPA s STORET database Files containing this data will also be available at the Bureau of Freshwater and Biological Monitoring web site (

10 Ambient Datasonde Site List 2008 Ambient W M A Site ID Water Body Location Date Deployed Date Recovered Date Deployed Date Recovered Yards CreekC Mount Vernon Road, Flatbrookville 06/24/08 06/27/08 09/03/08 09/05/08 Yards CreekB Mount Vernon Road, Flatbrookville 06/24/08 06/27/08 07/02/08 07/07/08 Bear Creek B Shades of Death Road, Blairstown 07/02/08 07/07/08 Bear Creek C Shades of Death Road, Blairstown 09/03/08 09/05/08 8 AN 0337 Neshanic River Route 514, Neshanic 09/23/08 09/25/08 18 Site 1 Raccoon Creek Russell Mill Road, Mullica Hill 07/15/08 07/18/08 18 Site 2 Raccoon Creek Mill Road, Mullica Hill 07/15/08 07/18/08 18 Site 3 Raccoon Creek Tomlin Station Road, Mullica Hill 07/15/08 07/15/08 18 Site 4 Raccoon Creek High Street, Mullica Hill 07/15/08 07/15/08