Bolsa Chica New Channel Effect on Shoreline

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.