Bolsa Chica New Channel Effect on Shoreline Water Quality

Douglas Moore, Ph.D. (OCPHL) Charles McGee (OCSD) Martin Getrich (OCPHL) Patrick Pham (OCEH)

Sampling Sites at Bolsa Chica State Beach and Huntington City Beach

Location of Future Channel and Two Added Study Sampling Sites: BCN and BCS

Bolsa Chica Wetlands after Channel Opening

Study Outline • Study utilized shoreline water quality data. • Pre-Channel June 7, 2005 – Aug 23, 2006 • Post-Channel Aug 24, 2006 – Aug 27, 2007

– 5 sample sites for Bolsa Chica Site • Channel Opened Aug 24, 2006 • 4 Beach Sites ((n = 190 to 450 p per site)) • 1 Mid-Channel Feb. 2007 – Aug. 27, 2007 (n = 25)

– 8 sample sites for Santa Ana River Site • Date range from June 7 7, 2005 – Aug. Aug 27 27, 2007 • 5 Beach Sites (n = 440 to 450 per site) • 3 Channel Sites ( n = 450 to 480 per site)

Study Details •

Collection & Testing g conducted by y Orange g County y Sanitation District. Total Coliforms, Fecal Coliforms, & Enterococcus Tested.

•

Data analysis by OC PHL & OC EH

•

Dry weather data only, rain periods excluded

•

Statistical Analysis – Geomean – Failure rates – single samples exceedances – Differences in values before and after channel opening • The Mann-Whitney U – nonparametric rank test

Bolsa Chica Enterococcus Data, All Sites N = 1289 Channel

3.00

Pre Post

104 CFU/ 100 ml

Lo og (ENT)

2 00 2.00

1.00

Geomean 5.2 CFU/100 ml

0.00 01/01

02/01 03/01

04/01

05/01

06/01

07/01

Date

08/01

09/01

10/01

11/01

12/01

01/01

Bolsa Chica Chica, Geomean of Single Sample Levels 30

CFU/100ml

25

Pre Channel

*

Post Channel

*

20 15 10 5 0 TC FC Ent TC FC Ent TC FC Ent TC FC Ent TC FC Ent 33N

BCN

CHAN

BCS

Site/Indicator

*

Statistically significant for p < 0.05, by Mann-Whitney U Test

27N

Samples E S Exceedan nces

Bolsa Chica Chica, % Single Sample Exceedance Pre Channel

6.0%

Post Channel

5 0% 5.0% 4.0% 3.0% 2.0% 1.0% 0 0% 0.0%

TC FC Ent TC FC Ent TC FC Ent TC FC Ent TC FC Ent 33N

BCN

CHAN

BCS

Site/Fecal Indicator Bacteria

27N

Conclusions Bolsa Chica Conclusions, • Opening channel did not degrade water quality at adjacent beaches in a one year y weather study. y dry • Water taken directly from channel has very g low concentrations of indicator organisms. • Study will be continued one additional y year. • Effect during rain events is unknown at this time.

Sampling Sites at Huntington State Beach/Newport Beach

Santa Ana River Region Enterococcus Data, All Sites N = 3624 Channel 3 00 3.00

Pre Post

104 CFU/100 ml

Log (ENT)

2.00

1.00

Geomean 8.0 CFU/100 ml

0.00 01/01

02/01

03/01

04/01

05/01

06/01

07/01

Date

08/01

09/01

10/01

11/01

12/01

01/01

SAR R Region, i G Geomean S Sample l Levels L l Geomean 90 80

CFU U /100 ml

70 60 50 40 30 20 10 0 TC FC Ent TC FC Ent TC FC Ent TC FC Ent TC FC Ent TC FC Ent TC FC Ent TC FC Ent 6N

3N

TM

0

SAR-N

Sample Sa peS Site te

SAR-S

3S

6S

SAR Region Region, % Single Sample Exceedances 16.0% 14.0%

Exc ceedance

12.0% 10.0% 8.0% 6.0% 4.0% 2.0% 0.0% % TC FC Ent TC FC Ent TC FC Ent TC FC Ent TC FC Ent TC FC Ent TC FC Ent TC FC Ent 6N

3N

TM

0

SAR-N

Sample Sa peS Site te

SAR-S

3S

6S

Exceeda ance

Comparison of Bolsa Chica and Santa Ana River Region Single Sample Exceedances 8% 7% 6% 5% 4% 3% 2% 1% 0%

* * TC

FC

Ent

TC

Bolsa Chica

FC Santa Ana River

Indicator/Sample Site

*

Statistically significant for p < 0.05, by Mann-Whitney U Test

Ent

Conclusions Santa Ana River Conclusions, • Channels degrade water quality at down current adjacent beaches. • Water taken directly from channel often has high concentration of indicator g organisms. • Other studies have shown high levels of enterococcus in channel sediment. • Dry weather beach failures are correlated p g tides. with spring

Bolsa Chica Wetlands Pollution Factors Storm Drains: None Drainage Area: Wetlands only Intertidal Area: Small but increasing when partial tidal area is opened. Bird Population: Yes ? Tidal Effect: ?

SAR/Talbert Channels Pollution Factors Storm Drains: Numerous in both SAR and Talbert Channel (diverted in dry weather) Drainage Area: Extensive below Prado Dam. Huge total area above dam. Intertidal Area: Large percentage of wet zone Bird Population: Yes ? Tidal effect: Beach pollution occurs during spring tides.

Conclusions • Bolsa Chica is an estuary with a channel that doesn’t degrade g water q quality y in dry y weather. • Certain factors may determine if an estuary will degrade surrounding water quality. Connection to storm drains is the main factor factor. • Routing storm drains through wetlands will possibly pollute the wetlands as well as the receiving water. • Ocean/Beach O /B h water t quality lit studies t di should h ld b be partt off Bolsa Chica operation. • Santa Ana River/Talbert Channel is an example p of a wetland/ storm drain system that pollutes adjacent beaches even with diverted storm drains. Cause should be determined through g further studies.