TMDL Rules Drive Water Monitoring

The Clean Water Act has since its adoption included provisions for the development and enforcement of Total Maximum Daily Loads (TMDLs) to address nonpoint source pollution in waterbodies that are deemed by the states to be "water quality impaired" - waters that do not meet state standards for their designated uses. But EPAs focus on mitigating point sources put TMDLs on the back burner for decades. Today, more than two dozen lawsuits have launched TMDLs to the forefront in states acro

Jan 1st, 1999

The Clean Water Act has since its adoption included provisions for the development and enforcement of Total Maximum Daily Loads (TMDLs) to address nonpoint source pollution in waterbodies that are deemed by the states to be "water quality impaired" - waters that do not meet state standards for their designated uses. But EPAs focus on mitigating point sources put TMDLs on the back burner for decades. Today, more than two dozen lawsuits have launched TMDLs to the forefront in states across the nation.

As the states and EPA scramble to identify impaired waterbodies and establish TMDLs, water quality agencies and watershed partnerships will be under increased pressure to develop watershed-wide monitoring protocols, establish cooperative working relationships and capture high-quality data.

"Theres a general consensus that there is a scarcity of data on many waterbodies that are suspected to be impaired," said Ed Wagner, a senior consultant at CH2M Hill in New Jersey, who served on a federal committee convened by EPA to generate advice on TMDLs. "In most waterbodies around the country, there isnt enough data to build a TMDL, so additional data will have to be collected."

TMDLs are extremely comprehensive and far-reaching. The process starts after a state identifies a waterbody as impaired and adds it to the states 303(d) list. For each pollutant listed for the stream, a TMDL identifies the water quality problem, quantifies it, and determines how much pollution can be attributed to each source in the watershed. The TMDL then specifies the reduction of the pollutant needed to meet state water quality standards for the waterbody in question, identifies mitigation tactics and allocates pollution control responsibilities to each source in the watershed. State and federal discharge permits can be altered to conform to the TMDL.

Shift in focus and locus

First-rate water quality data are crucial throughout the TMDL process. States will be compelled to shift resources to collect data for TMDLs, Wagner said. The emerging shift toward analyzing quality issues on a watershed basis will continue, too.

Shift in focus and locus

"Most states have monitoring programs designed to assess long-term trends, but at least until recently have not been focused on a watershed basis," he said. "They have to integrate sampling of flow, runoff and discharge." Individual dischargers, such as municipalities and industry, will also find it important to invest in good data collection, Wagner said.

Shift in focus and locus

"Anybody who might be affected by more stringent requirements by TMDLs - and that is a large number of people - theyre motivated to provide more data to make sure theres adequate and accessible data on which to build the TMDL," he said.

Shift in focus and locus

A glance through the 303(d) list indicates that water quality monitors will soon see some parameters become increasingly important.

Shift in focus and locus

"The standards - for instance temperature, dissolved oxygen, pH and salinity - will need to be there for background. But sediment loads are going to be, in some cases, monitored where they havent been. And in-stream turbidity systems will become important too. Theres such a direct connection to nonpoint source problems," said Wes Jarrell, professor of environmental science and engineering at Oregon Graduate Institute in Portland, Ore., and chair of four technical committees during the development of the TMDLs for Oregons Tualatin River. TMDLs have been in force on the Tualatin since 1988.

Shift in focus and locus

Notes Allison Shipp, TMDL coordinator for the U.S. Geological Surveys Water Resources Division, understanding the behavior of sediment at various depths is going to be crucial to developing TMDLs and monitoring their success.

Shift in focus and locus

"We also see more real-time data being needed or desired to better understand flow and transport," she said.

Shift in focus and locus

The deployment of monitoring equipment may also change significantly in some watersheds as regulatory agencies and watershed watchdogs assess how individual land users contribute pollutants to the affected waterbody. Rather than logging the overall levels of contaminants in a stream, "youre looking for sources - its the next level of intensity," said Jarrell.

Shift in focus and locus

That means monitors may increasingly be positioned at the transitions between various land use types.

Shift in focus and locus

"We could pick the points where the hills meet the valley floor - thats the junction between forestry and agriculture," said Jarrell as he recalls the development of the Tualatin TMDL. "In Oregon, we then go to the urban growth boundary and find the junction between agriculture and urban land use."

Shift in focus and locus

Once the TMDL is written, regulators may have to work their way upstream to find specific land users who are not in compliance.

Shift in focus and locus

"Theyll try to narrow that down by subdividing the stream and find the largest change in water quality, then follow that back to the source," said Jarrell.

Unattended monitoring improves data

TMDLs will likely also accelerate the trend toward long-term, unattended monitoring.

Unattended monitoring improves data

"Theres no question that long-term, continuous data are far and away the most useful. As happens a lot in nature, especially in urban systems when you screw up the hydrology, intermittent events disturb the system," said Jarrell, who noted that even brief changes in dissolved oxygen levels can kill large numbers of fish and other aquatic organisms during a storm. "Being able to snag those extreme events - extreme in nature even if theyre short in duration - is going to be very important."

Unattended monitoring improves data

Greg Aamodt, environmentalist with Carver County Environmental Services in Chaska, Minn., said he relies heavily on automatic data collection as he tracks a suite of parameters ranging from suspended solids to nutrients.

Unattended monitoring improves data

"Just going out and grabbing samples wont do it," he said. "If you dont have a regular regime with an automatic system, you cant replicate it with humans - its just impossible. And its a stretch of the imagination that youre going to have someone out there in a storm event taking samples every hour."

Unattended monitoring improves data

Sophisticated automatic sampling systems are helping fill the growing need for real-time data, too. "Its really important in modeling," said Shipp at USGS. "The more data you have, the better, so the information from unattended instruments are very important as we calibrate the models.

Unattended monitoring improves data

"A legacy pollutant like dioxin may not need to be sampled in real time," Shipp added. "But for certain parameters such as temperature and dissolved oxygen - which are so important to the biotic community - we need to have that available in real time."

Unattended monitoring improves data

Monitoring equipment prices have fallen in the last decade, making unattended monitoring more feasible for many water monitoring groups.

Unattended monitoring improves data

"You can purchase a system that measures four or five parameters for $3,000," said Gayle Rominger, vice president for environmental monitoring systems for YSI Incorporated in Yellow Springs, Ohio. "And for as little as $2,000, you can add a data collection platform that would allow you to do long-term, unattended monitoring. If you compare that to grab sampling labor and analysis, thats pretty economical."

Driving innovation in equipment

The complexity of TMDLs and the importance of setting priorities - especially as court judgements set tight deadlines of TMDLs in many states - is pushing design innovations in monitoring equipment.

Driving innovation in equipment

"Our goal is to provide people with the tools to get good, high-quality, long-term data by which they can make decisions. Then they can spend their resources mitigating problems they know and understand," Rominger said.

Driving innovation in equipment

Driven by the demand for more information, each generation of monitors features longer battery life and greater versatility. Rominger said the need for continuous nutrient monitoring has led her company to research several sensor technologies that would bring that capability to the field.

Driving innovation in equipment

Manufacturers are also honing the tools that help water monitoring specialists crunch the numbers. For instance, YSI is putting the finishing touches on its EcoWatch for Windows analytical software, which combines data from the companys multi-parameter sampling equipment and other inputs and can be exported to other water quality database programs such as EPAs BASINS and STORET for further analysis.

Organize now for tomorrows TMDL

As the push to develop TMDLs continues, state regulators, local agencies, landowners and other parties with a stake in the affected watersheds will play key roles in establishing baselines, developing achievable water quality standards and assigning pollution control responsibilities among sources.

Organize now for tomorrows TMDL

Organizing watershed partnerships and seeking expertise from inside and outside the watershed are extremely important steps to prepare for TMDLs. Members of watershed partnerships can team up to share equipment, protocols and data.

Organize now for tomorrows TMDL

"We were blessed with a lot of local talent," said Jarrell of the Tualatin TMDL effort. "It went a long way toward standardizing and interpreting results, and raising the technical ability and understanding of the people in the watershed."

Organize now for tomorrows TMDL

Seeking help from experts in other regions of the country can help watershed partnerships avoid reinventing the wheel, Jarrell added. He said joining a national phosphorus technical committee exposed him to techniques and approaches to phosphorus management that were being developed in the mid-South.

Organize now for tomorrows TMDL

Gathering baseline data now can help guide the TMDL process later. In Minnesota, Aamodt is developing an extensive database on sites throughout Carver County in preparation for a state-mandated Water Management Plan. If TMDLs are required someday, Aamodt figures Carver County will be ready.

Organize now for tomorrows TMDL

"I think it will definitely give us a head start," he said. "Weve got data in place indicative of where we are, indicative of whether we are improving or sliding backwards."

Organize now for tomorrows TMDL

Jarrell noted that good baseline studies helped direct the Tualatin River TMDL away from unachievable phosphorus reduction goals.

Organize now for tomorrows TMDL

"We have naturally phosphorus-rich sediments in our agricultural and urban soils," he said. "It took us a long time to show that these were sources of phosphorous that were uncontrollable without heroic engineering efforts which would trash the environment worse than the phosphorus. There were 50 other things we could do to improve the stream more than if we lowered phosphorus in the specific watershed. However, phosphorus management will be key to many, if not most, watersheds that are affected by humans."

Organize now for tomorrows TMDL

TMDLs can even result in modifying water quality standards to better reflect the effects of a pollutant in the ecosystem. For instance, the standards for copper in the New York/New Jersey Harbor estuary were revised to focus on dissolved copper, noted Wagner, who represented the New York City Department of Environmental Protection on the estuary program before becoming a consultant. The old standards included all forms of metals in the water, Wagner said. Studies to develop TMDLs for copper in the estuary determined that only the dissolved form of copper was bioavailable to most species, so the standards were changed.

Organize now for tomorrows TMDL

There are plenty of bumps on the road to an objective as complex and politically charged as a TMDL. But the critical component in the process - as critical as data and valid models - is taking the time to build cooperation among stakeholders, Wagner said.

Organize now for tomorrows TMDL

"You can do the numbers and crunch through them, but its more than science to do a TMDL. Its more a policy question of who gets the allocation, how much each stakeholder will be allowed to discharge," he said. "To do that in a way that people will accept generally takes their participation. It takes time to do that."

Organize now for tomorrows TMDL

The months or years it takes to pull stakeholders together could be time well spent. Said Rominger of YSI, "Coordination is an outgrowth of the TMDL approach. I think that will be one of the benefits to come out of this, because its just too big for any one group to do by itself."

About the Author:

Steve Werblow is a freelance writer with 10 years experience writing on agricultural and environmental resource topics.

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