Morro Bay National Estuary Program

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Morro Bay National Estuary Program Volunteer
Monitoring Program
Stormwater Pollution Local Data and How you
can Help
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First Flush
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What is First Flush Monitoring?

• Collection of urban runoff from storm drains
  during the first large rainstorm of the season.
• Pollutants and particulates have accumulated for
  several months.
• Produces the most contaminated runoff of the
  season.

Goals of First Flush Monitoring

• Identifies pollutants of greatest concern in the
  watershed.
• Highlights areas where particular contaminants
  need to be addressed.
• Increases public awareness of storm drainage into
  the bay.

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Historic First Flush monitoring in the watershed

• 26 Sites in Morro Bay and Los Osos.
• Conducted by NEP and RWQCB.
• Included culverts, drainage ditches, and known
  flood prone areas.
• Monitored 95, 96, 97 for heavy metals,
  bacteria, water quality parameters.

Drainage culvert at Marina and Embarcadero.
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What contaminants are being monitored?

• Oil and Grease
• Heavy metals Zinc, Copper, Lead and Nickel
• Pathogenic Bacteria Total Coliforms and E.Coli
• Suspended and Dissolved Solids Sediment and
  suspended particles
• Nutrients Orthophosphates and Nitrates
• pH Acidity
• Dissolved Oxygen
• Turbidity

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First Flush Monitoring Effort

• Volunteers collected samples
• Samples analyzed in house for bacteria and water
  quality parameters.
• Samples sent to lab for additional analysis.
• Complete sample analysis cost approximately 200
  per site.
• Funding provided by the NEP.

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Selection of Sites

• Mixed land uses commercial, residential, parks.
• Large culverts with direct drainage into the bay.
• Flood prone low lying areas.

How do you know when to monitor?

• Monitoring initiated when sheet flow was observed
  on streets.
• 8 sites successfully monitored throughout Morro
  Bay and Los Osos.
• All samples collected within 1 hour of sheet flow
  observation.

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2007 First Flush Sites
City of Morro Bay
Los Osos
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Regulatory standards for stormwater or lack
thereof

• Standards for safe recreational contact in
  creeks, bays or oceans
• Standards for receiving waters, must be
  maintained following a flush.
• Event Mean Concentration shows average
  contaminant concentrations runoff from different
  land use types.

Standards Applied for 2007 Data

• 235 MPN/100ml E. Coli Bacteria
• 10 µg/ L copper and lead
• 2 µg/ L nickel
• 20 µg/ L zinc

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E. Coli test results

• EPA guidance is 235 MPN/100ml.

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Dissolved metals are far above the regulatory
standard for the estuary.
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Nutrients in First Flush Samples Orthophosphates

• All Sites Exceeded recommended levels, firm
  standards are not in place.

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Nutrients in First Flush Samples Nitrates

• Relatively low levels

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Urban Watch Monitoring Sites in Los
Osos Methods Visit 1x per week, make
observations and collect samples if flow was
present Test for Nitrate, Temperature pH Colif
orm (bacteria) Chlorine Turbidity
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Table 13. Overview of observations from 2007 and
2008 UW monitoring. City Site Code of
Observations with Flow 2007 2008 Los Osos
BVH 92 85 ASHS 50 62 ASHN
25 62 FAR 0 15 PNE 0 7.6
BPR 8.3 50 Morro Bay RMP 30
61 BWD 58 33 NTD 53 76
NTD2 0 41 PCF 53 35 PCF2
0 0 ROS 89 88 DUN 0 6
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The Results Overall

• Oil and Grease was not detected in any of the
  samples.
• Rainfall intensity, particle adherence.

• Metals concentrations elevated throughout
  slightly higher in MB than Los Osos
• Turbidity and Bacteria concentrations elevated
  for Los Osos samples versus Morro Bay.
• Dissolved oxygen , pH and nitrate were not above
  levels of concern.
• Stormwater is flowing in the dry season this is
  bad for water supply and for water quality

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What You Can Do About Stormwater Pollution

• Limit use of fertilizer and pesticides
• Dispose of chemicals at the household hazardous
  waste facility in MB
• Pick up after your pets
• Get all auto leaks fixed promptly
• Wash your car at a carwash, or over grass or
  sand.