Difference between revisions of "TMDL for Fecal Coliform for the Lower Salinas River Watershed, Monterey County, California"

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(Source Analysis)
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TMDLs are required to include a margin of safety that accounts for uncertainty in the linkage between loading capacity of the watershed and pollutant concentration in the receiving water.  In the case of fecal coliform, the goal is for all controllable water sources to meet the target concentration.  As this is not a load-based approach, no margin of safety is given.
 
TMDLs are required to include a margin of safety that accounts for uncertainty in the linkage between loading capacity of the watershed and pollutant concentration in the receiving water.  In the case of fecal coliform, the goal is for all controllable water sources to meet the target concentration.  As this is not a load-based approach, no margin of safety is given.
  
==Critical and Conditions and seasonal variation==
+
==Critical Conditions and seasonal variation==
 
This TMDL does not identify any "critical" environmental factors, in which a slight change could lead to exceedence of water quality objectives.  However, it is noted that pollutant concentration is dependant on flow volume, which is often irregular in our climate.  Also, localized areas of stagnant water with fine sediments are favorable for bacteria propagation, and may increase concentrations of Fecal Indicator Bacteria.
 
This TMDL does not identify any "critical" environmental factors, in which a slight change could lead to exceedence of water quality objectives.  However, it is noted that pollutant concentration is dependant on flow volume, which is often irregular in our climate.  Also, localized areas of stagnant water with fine sediments are favorable for bacteria propagation, and may increase concentrations of Fecal Indicator Bacteria.
  

Revision as of 19:07, 21 March 2010

An summary of the Regional Water Quality Control Board Central Coast Region report on Total Maximum Daily Load for Fecal Coliform for the Lower Salinas River Watershed, Monterey County, California [1] by the Spring '10 ENVS 560/L Watershed Systems class at CSUMB.

Project Definition

This report investigates the impairment of the Lower Salinas River and several of its tributaries as a result of increased fecal coliform concentrations in accordance with Section 303(d) of the Clean Water Act. The biological impairment of a river can result from microbial pathogens (viruses, protozoa's, and bacteria) that can be readily correlated with fecal coliforms. As a result, fecal coliforms are used as indicator species for water body contamination. The Lower Salinas watershed is used for a variety of purposes including, but not limited to: groundwater recharge, wildlife habitat, industrial and agricultural supplies, commercial and recreational fishing and recreational activities. As a result, understanding water body impairment due to microbial pathogens is important for human health and safety as well as environmental sustainability and improvement.

Watershed Description

The area of concern for this TMDL is the lower 400 square miles of the Lower Salinas Valley and includes two major watersheds, the Reclamation Canal and Lower Salinas River. The Reclamation Canal watershed drains into the Old Salinas River and includes Tembladero Slough and its tributaries, while the Lower Salinas Watershed drains into the Salinas River Lagoon and includes Blanco Drain, Toro Creek, Quail Creek, Chular Creek and other tributaries of the Salinas River. While there is some hydrologic connectivity between the two, it is highly limited, thus the Reclamation Canal and Lower Salinas River are essentially two separate watersheds. The project area boundaries are the Gabilan Range to the east, the Sierra de Salinas range to the west, and the Monterey Bay to the north east.
TMDL Project Area

Problem Statement

The Lower Salinas River and nine of its tributary water bodies are listed as impared under section 303(d) of the Clean Water Act due to elevated levels of fecal coliform. Observed levels of fecal coliform are not protective of the following beneficial uses designated for some or all these water bodies:

  • Water contact recreation.
  • Non-contact water recreation.
  • Shellfish harvesting for human consumption (under review).

Data Analysis

Water Samples Use of fecal indicator bacteria (FIB) tests have placed the Salinas Watershed on the Impaired list. FIB tests identify indicator bacteria for pathogens resulting from fecal coliform. Data used in this study was from as far back as February 1999.

Data sources for the TMDL came from:

  • TMDL Project data set
    • From TMDL Project and USDA
  • Central Coast Ambient Monitoring Program (CCAMP)
  • Entities regulated by the Central Coast Water Board (City of Salinas Stormwater Program)
  • Central Coast Watershed Studies (CCoWS) Team (affiliated with the Watershed Institute at California State University-Monterey Bay)
  • Snap Shot Day monitoring program (Monterey Bay National Marine Sanctuary Citizen Watershed Monitoring Network)

Problems with water sample tests These tests have many problems because not all fecal coliform is a pathogen. A separate test can identify presence of E. Coli in the water sample, however these tests have the same problem of only sampling an indicator, not a pathogen.

...What are the indicators? How did they come up with the numbers?...

Source Analysis

Sources of fecal coliform in the Lower Salinas Watershed were identified to arise from various sources. These included:

  • Point Sources - a single identifiable localized source of pollution (i.e. you know exactly where the pollution is coming from and can quantify it).
    • Storm drain discharges to storm sewer systems
    • Spills and leaks from sanitary sewer collection and treatment systems
    • concentrated animal feeding operations and dairies
  • Nonpoint Sources- pollution derived from many different diffuse sources (i.e. regulation of one point or source will not rectify the problem).
    • Domestic animal discharges in areas that do not drain to a storm water sewer system
    • Onsite waste disposal systems
    • Illegal Dumping
    • Homeless Encampments
    • Sediment Sources
    • Runoff from Irrigated Agriculture
    • Non-controllable natural sources (wind-borne debris)

Numeric Target

The TMDL for fecal coliform is designed to acheive a concentration where the log mean over any 30 day period does not exceed 200 MPN per 100 mL, and no more than 10 percent of samples exceed 400 MPN per 100 mL.

Linkage Analysis

The Linkage Analysis is intended to link the numeric target concentration (amount per volume) to a daily load (amount per day) for the watershed. In the case of fecal coliform, the RWQCB expresses the intent to implement the TMDL based on the target concentration rather than load allocation.

TMDL Development

The TMDL for fecal coliform is based on a three tiered flow regime, wherein each water body has different allowable loads established for high (top 5%), moderate (middle 25%), and low (bottom 60%) flows. Allowable loads are calculated by multiplying the average flow within each flow regime (low, moderate, or high) by the target concentration [volume/time * mass/volume = mass/time]. These target loads were compared to existing loads derived from field data to determine where exceedences are greatest or most frequent.

Margin of Safety

TMDLs are required to include a margin of safety that accounts for uncertainty in the linkage between loading capacity of the watershed and pollutant concentration in the receiving water. In the case of fecal coliform, the goal is for all controllable water sources to meet the target concentration. As this is not a load-based approach, no margin of safety is given.

Critical Conditions and seasonal variation

This TMDL does not identify any "critical" environmental factors, in which a slight change could lead to exceedence of water quality objectives. However, it is noted that pollutant concentration is dependant on flow volume, which is often irregular in our climate. Also, localized areas of stagnant water with fine sediments are favorable for bacteria propagation, and may increase concentrations of Fecal Indicator Bacteria.

TMDL Allocations

Allocations are given as target concentrations. For non-human fecal indicator bacteria, all allocations are the same as the target concentration stated above. Rhe allocation for human FIB is zero. Load-based allocations, based on the method described in the 'TMDL development' section above, are also given in Table 7-7 of the TMDL report.

Public Participation

here are many stakeholders in the Lower Salinas Watershed that are affected by the implementation of the fecal coliform TMDL. These would include:

  • Agricultural
  • Industry
  • Sewer discharge facilities
  • Wildlife
  • Fisheries
  • Sporting recreational activities
  • Municipal and domestic water supply
  • Homeless Persons

Implementation and Monitoring

The goal of implementation and monitoring is to reduce pathogen loads and achieve the stated TMDLs for the Salinas River Watershed. Potential pathgoen sources include: municipal storm drain discharges, domestic animal/livestock discharges, illegal dumping, discharges from homeless persons/encampments, sanitary sewer collection system spills and leaks, wildlife, and sediment bedoad resuspension. Because of the complexity involved with coordinating all these various sources for patholgoical pollutants the report lays out an implementation and monitoring road map to identify key aspects, and make sure progress is recorded and results obtained.

Implementation

  • Implementation Actions
  • Evaluation of Implementation Progress
  • Timeline and Milestones
  • Economic Considerations

Monitoring

  • Monitoring Sites
    • Frequency
    • Responsible Parties

Monitoring Plan

Laws and Policies

The law which creates the TMDL process is the Clean Water Act(CWA). The CWA defines a TMDL as "a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards, and an allocation of that amount to the pollutant's sources."

Future research

While fecal coliforms are useful indicators of pathogenic biological organisms they do not prove their presence/absence. As a result, future research needs to be focused on developing quick, cheap and efficient tests for a wide range of pathogenic organisms. This could be accomplished with the use of DNA chip technology, and or microarrays.

  • Possibly covered in the data analysis section.

References

  1. Total Maximum Daily Load for Fecal Coliform for the Lower Salinas River Watershed, Monterey County, California

Links

Disclaimer

This page may contain student work completed as part of assigned coursework. It may not be accurate. It does not necessary reflect the opinion or policy of CSUMB, its staff, or students.