Environmental Protection

Germ Warfare

San Diego Water Authority leads charge to establish TMDLs for bacteria-impacted waters

The San Diego Regional Water Quality Control Board, in one of its most ambitious programs to date, proposes to set up rules that will reduce bacteria in stormwater runoff that flows to the coastline. In the past, the board has targeted chemicals. Now it is proposing to tackle bacteria, which originate in the intestines of warm-blooded animals (such as birds, feral cats, pets, livestock, horses, and humans) and have chronically exceeded safe levels. Pollution warnings have been commonplace.

Fecal bacteria have long been measured as an indicator of human pathogens in water. Those pathogens threaten the health of recreational users and those who eat shellfish. The board has made bacteria reduction a priority due to the human health concern and the potential economic losses associated with beach closures. There are huge challenges to identifying and controlling the myriad natural nonpoint sources of bacteria in the watershed, including the cost to cities and counties that must implement the board’s ultimate order.

In 2003, the Regional Water Quality Control Board for the Los Angeles region (Long Beach to Ventura) adopted a basin plan amendment that established total maximum daily loads (TMDLs) for bacteria after obtaining state and federal approval. All regions within its jurisdiction are covered during “wet weather,” whereas certain “reference” areas, including Santa Monica Bay beaches, were identified for “dry weather” while more information is gathered from other areas. It is still too early, according to one staff member knowledgeable about the local process at the San Diego board, to comment on its effectiveness or cost.

Southern California is not the only region facing these issues. Other regions across California, such as Tomales Bay and Napa River, and all across the country, including parts of the lower Mississippi and Chesapeake Bay, have recently approved TMDLs for bacteria or are in the process of doing so.

The legal authority for the bacteria order starts with Section 303(d)(1)(A) of the Clean Water Act, which states, “Each state shall identify those waters within its boundaries for which the effluent limitations … are not stringent enough to implement any water quality standard applicable to such waters.” The board must develop TMDLs to restore such waters.

The board defines TMDLs as “the sum of the individual waste load allocations for point sources and load allocations for nonpoint sources and natural background such that the capacity of the waterbody to assimilate pollutant loading (the loading capacity) is not exceeded.” In other words, the board divides and allocates the maximum pollutant standard among all the contributing sources.

Bacteria-impaired waters
The San Diego board first proposed in 2003 to address 19 of the 38 bacteria-impaired waterbodies with new TMDLs, from San Diego to southern Orange County. The board identified those waterbodies in its 2002 List of Water Quality Limited Segments, updated in 2006, which was compiled pursuant to Section 303(d). After drafting a technical report, seeking public input, and a series of revisions, the board on April 25 held a public hearing on the proposed basin amendment to include numeric targets in the TMDLs for bacteria. A follow-up hearing was planned for June 13. A final decision will not likely occur until this fall, and that will be subject to state and federal regulatory approval.

There are 12 different watersheds that contribute runoff to the coastline subject to the proposed TMDLs, each with unique attributes and sources. Twenty-six cities, Orange and San Diego counties, Caltrans, flood control districts, and owners/operators of stormwater drains will be swept up by these new TMDLs. The magnitude and complexity of the issues is staggering.

Specifically, the board is seeking to amend its basin plan, pursuant to California’s Porter- Cologne Water Quality Act (under Section 13240 of the Water Code), in order to add the proposed TMDLs. If amended, the plan would then affect creeks, shorelines, and creeks discharging to the ocean. The board also must prepare an environmental impact report under the California Environmental Quality Act in conjunction with the amendment. Stringent numeric levels are designed to protect not only human health but also shellfish harvesting from bacteria.

The board will implement new TMDL requirements, primarily by inserting them into National Pollutant Discharge Elimination System (NPOES) permits for storm drains as coastal communities seek permit renewal. Storm drains are treated as point sources, yet they are hardly like point sources in the historical sense, such as an industrial discharge from a facility. Nearly all upstream nonpoint sources merely funnel runoff through such drains at the end point, making them a practical target of regulators.

NPDES permitees will be required to develop bacteria load reduction plans, use “best management practices,” and implement monitoring components to achieve those goals. The board also considers the Porter-Cologne Water Quality Act to be its principal source of authority to regulate nonpoint sources with TMDLs. “Management measures” will be used to reduce nonpoint loads.

No uniform runoff
In preparing TMDLs, the board used models that took into account episodic storms in which high levels of bacteria enter the coastline as well as “dry-weather urban” runoff, given San Diego’s limited rainy season. Wet-weather flows are defined as 0.2 inches of rain or more in any 72-hour period. Dry-weather flows include all other times; these often are caused by excess irrigation and by washing cars and hardscapes.

The runoff is not uniform. Moreover, a portion of urban runoff that does not enter a storm drain comes from “uncontrollable” sources, such as birds and wildlife. The board claims it will focus on controllable sources. The TMDLs, however, must be met regardless of the source. There are concerns among the cities and counties that the net effect is to have a “zero” discharge policy from all non-natural sources.

The board has not yet decided whether it will allow a certain number of days of exceedances, as allowed by Los Angeles. Because rainy days cause an uncontrollable deluge of bacteria and contaminant-laden runoff to surge through storm drains to the coastline, exceedances are inevitable given today’s storm drain configuration.

There is a certain leap of faith in the board’s approach. The board openly states limitations may change over time as better scientific understanding of the interplay of bacteria and human health evolves. For instance, the board acknowledges that spikes in bacteria associated with urban runoff do not necessarily correlate with increased human pathogens, citing local studies done in 2003 and 2004. In one example, bacteria “regrows” and peaks at low tides in eel grass and likely does the same in storm drains during tidal fluctuations. As can be imagined, that regrowth phenomenon is one of the significant challenges cities will face. The regrowth then competes, along with bird and other animal wastes, with bacteria loads from other sources. It also is not clear whether birds, which do not come in contact with humans, carry human pathogens.

More studies are needed to better correlate bacteria with pathogens. As noted by Mo. Lahsaie, the Clean Water Program coordinator for Oceanside, Calif., cities must identify the sources of bacteria, both anthropogenic and natural, in the watershed affecting their jurisdiction. Oceanside is under the jurisdiction of the San Diego board.

Cities typically compete for limited grants to help fund their investigation. After identifying the sources, Lahsaie states their task will be to eliminate them. Residential and agricultural sources are particularly difficult to control, he said. Of course, there will be an educational component to make residents aware of the issues, leading, perhaps, to enforcement and penalties for noncompliance. That is virtually inevitable as communities will face threats of citizens’ suits for violating their NPDES permits.

Diversions and more treatments
Some cities are diverting or considering how to divert dry water flows before they enter creeks and rivers. Others, like the city of Oceanside, may have to install more ultraviolet light or ozone treatments at the mouths of creeks and rivers. In the end, if the communities are unsuccessful at meeting the

TMDL requirements upstream of the storm drains, they will have to address them by diverting runoff from the storm drain to sanitary sewers. The capital expense to install piping and expand sanitation facilities will be, well, incapacitating in many instances.

Compliance must occur within 10 to 17 years, depending on location. Differences depend on, for example, amount of swimmer use, whether shellfish are harvested or not, and frequency of exceedances for a particular area. NPDES permittees have a formidable task ahead, not only in terms of finding technical ways to comply with the TMDLs but finding the money to do so. How much will it cost?

The estimated upper range by larger permittees goes up into the billions. Whether that proves to be the case remains to be seen. The imposition of the bacteria TMDLs in San Diego will not be immediate, with the measures that will be used still in formulation. Next in line are TMDLs for San Diego Bay and Dana Point Harbor. The board has ordered coastal communities to investigate the impact of bacteria, nutrient, and sediment loads to lagoons and provide necessary data for the board to then formulate TMDLs. You can be sure the cities and counties will relish picking their poison.

The link to the San Diego board’s Web site regarding this issue is http://www.waterboards. ca.gov/sandiego/tmdls/bacteria.html

This article originally appeared in the 07/01/2007 issue of Environmental Protection.

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