Proposed Toxicity Regulations – What Are They and Why Should We Be Concerned?

The State Water Board is about to approve a new regulatory testing procedure on Toxicity. We spoke with Adam Link, Director of Government Affairs for the California Association of Sanitation Agencies (CASA), Steve Jepsen, Executive Director of Southern California Alliance of Publicly Owned Treatment Works (SCAP) and Lorien Fono, Regulatory Program Manager, Bay Area Clean Water Agencies (BACWA) to learn what this new regulation means how it will impact wastewater labs and what water professionals can do to help.

Adam Link, Director of Government Affairs for the California Association of Sanitation Agencies (CASA)

Steve Jepsen, Executive Director of Southern California Alliance of Publicly Owned Treatment Works (SCAP)

Briefly, what is toxicity in layperson terms?

Lorien: Toxicity is a way of measuring the impact of effluent on aquatic organisms. You take the organisms assigned by your permit, expose them to effluent, either at 100% or diluted depending on the test and your permit requirements, and observe their response. For acute toxicity, you’re observing how many, if any, organisms die compared to the control group, which are in lab water. For chronic toxicity, you look at endpoints such as growth or reproduction, compared to the control group. Acute is a one or to three-day test, chronic takes about a week.

Adam: Something important to note about toxicity generally, is the perception about what it means versus the reality. Something labeled “toxic” based on these tests doesn’t mean the water or effluent is actually toxic. It’s more about the affect on endpoints such as reproduction of the organisms, and any water quality inferences drawn from those. We need to make clear that getting a hit for toxicity does not mean water is toxic.

Steve: Toxicity or Toxic is a strong word that brings up concerns from the public. When we talk about toxicity in wastewater it is in terms of laboratory tests with extremely sensitive living organisms. As an example,  tap water that’s safe for humans to drink is toxic to aquarium fish.

What is the current standard for toxicity testing, and where are we heading?

Lorien:  Two major changes are proposed right now via the State Toxicity Plan, which is expected to be posted for public comment later this year. In the past, toxicity has been regulated with triggers. Here in Region 2 [San Francisco Bay Region] everybody has a chronic toxicity trigger in their NPDES permit. If you exceed a certain threshold for toxicity, you embark on a toxicity identification evaluation (TIE) or a toxicity reduction evaluation (TRE). The agency tries to figure out what’s causing the apparent toxicity and see if they can get rid of it. The first change is that instead of having chronic toxicity triggers, the State is proposing a Plan to mandate enforceable numeric limits. If you get a toxicity hit that’s above a threshold, you violate your permit.

The other change is how toxicity is measured. The test itself is staying the same. You’re still exposing organisms to effluent and observing endpoints, but you’re taking the resulting data and interpreting it using a different statistical method. In Region 2, historically we’ve used the Inhibition or Effective Concentration (EC25/IC25) that measures the concentration where you see a 25% toxic effect, where the organism grows 25% less than the control group, or it reproduces 25% less than the control group. You measure toxicity at different effluent concentrations. You look at the dose response curve for toxicity and figure out at what concentration where you start to see that 25% toxic effect.

The new statistical method that will be required by the State Toxicity Plan, and that is already required by some Regional Water Boards, is the Test of Significant Toxicity (TST). With the TST, we are only interested in looking at toxicity at the instream waste concentration. If you have an effluent dominated receiving water, it’s going to be 100% effluent. Let’s say your effluent is diluted by a factor of one, so one part receiving water to one part effluent. That means that your effluent would be 50%. You’re doing the test at that specific concentration, and even though the EPA method still requires you to do a dose response curve, none of those other concentrations are meaningful in how the test is interpreted. You end up with the statistics giving your test a pass or a fail at that one specific effluent concentration.

Steve: In the past, and currently, it’s a multi concentration test that provides a curve where you can see results. If there’s erratic results, you know there was an issue with the test and it might mean the water isn’t actually toxic. In southern California, the Water Boards with EPA oversight have drafted some NPDES permits using the Test of Significant Toxicity (TST), which is an un-promulgated statistical pass-fail endpoint test. When you combine the TST with extremely sensitive test species, like the tiny water flea Ceriodaphnia dubia, it leads to an alarming amount of false positives for toxicity.

The Southern California Alliance of Publicly Owned Treatment Works (SCAP) is arguing against the legality of the TST test method and the test method being written into NPDES permits. It’s concerning because it has a big burden on agencies and it can lead to false positives. When toxicity is found, even if false, the agency has to investigate what is causing the toxicity by performing costly activities such as Accelerated Monitoring, Toxicity Reduction Evaluations (TRE), and Toxicity Identification Evaluations (TIE). False positives can also lead to permit violations or fines for the agency.

Adam: An important thing Lorien and Steve picked up on is that things are different across the state. When we say, “What is the current standard for toxicity,” it depends on the region, and even within regions, whether your permit was renewed recently. Some are operating under the old system. Region 4 [Los Angeles Regional Water Board] just started putting TST into new permits. There isn’t yet a state-wide standard for toxicity.

In addition to the statistical methods change, the state and regional boards are moving from narrative to numeric limits. That can have consequences in terms of liability for cities and agencies. They could receive frequent violations and face the threat of third-party lawsuits.

Lorien: It’s unfortunate we’re heading in this direction because the concept behind toxicity is that if you see an apparent toxic effect, you follow up on it and hopefully can address the cause. Where we’re heading with the State Toxicity Plan is if you see an apparent toxic effect, you’re given a violation. You may never have the opportunity to investigate it at all until after you already have violated your permit.

Tracking toxicity seems a worthy goal. Why should water professionals care about where this is going?

Lorien: The concept behind toxicity is a worthy one. It allows us to look for unknown unknowns. We have a number of regulated priority pollutants that reflect old industrial chemicals we’re not seeing anymore. Today, there’s a plethora of new compounds in the marketplace – new industrial chemicals, pharmaceuticals, personal care products, pesticides. The idea behind toxicity testing is to look for chemicals that aren’t being regulated and try to figure out what’s causing any apparent toxicity.

Decades ago, back when we had big problems from metals, legacy pesticides, and industrial chemicals, we would often see a large toxic signal where they cause could be identified. These days, we see low-level persistent toxicity, or toxicity that comes and goes so we can’t figure out what is causing it. Once the State Toxicity Plan comes into effect we might end up in a situation where agencies are constantly in violation but can’t figure out what’s causing the toxicity, and can’t address it.

There’s also some evidence current low-level toxicity is caused by pesticides, and wastewater agencies have no authority to regulate pesticides. They’re not covered by the Clean Water Act. They’re covered under the Federal Insecticide Fungicide and Rodenticide Act (FIFRA). We can do our best to advocate for changing pesticide regulations, but we cannot control how customers in our service areas use them.

Steve: We’re very used to permits having numerical limits on known constituents, like phosphorus or nitrogen. When it comes to toxicity testing, initially, we’re not looking for a particular constituent. It’s a test to see how this water affects living organisms. It’s looking for the unknowns that may be transient.

Adam: Our biggest concern is how the tests are characterized and which tests are used to determine toxicity. It was more valuable to identify the types of identifiable industrial sources Lorien identified in the past, but now we’re much more keenly aware of the sources of toxicity. It’s a mixture of pesticides, pyrethroids and other consumer products that are not within our control. It’s usually an isolated slug or something going through the system, so many times the TIE/TRE are not valuable exercises.

That is why water professionals should be concerned, because the changes have consequences on potential violations and liability. The steps agencies are going to have to take are so expensive they are disconcerting. Moreover, I’m not sure those steps are valuable and will accomplish the goals the Water Board is looking for.

What worries you most about this process?

Adam: The most concerning thing is that these toxicity tests are not very reliable. Some of the species being tested have high variability, so the results may not be reliable.  These are also some of most expensive tests we can run.

Steve: It’s difficult to estimate actual costs because we don’t really know how many false positives we will find. We’ve had experts estimate the economic impact of chasing down false positives could be as high as $40 million a year for California wastewater agencies.

Lorien: In Region 2, we’ve spent millions of dollars during the last permit cycle on TREs and we’ve not found anything during those investigations. One chronic toxicity test costs about $3,000. In the State Plan as proposed, if you see toxicity, you go into accelerated monitoring, then a TRE/TIE. Once you start, you’re doing more and more of those toxicity tests, so it quickly snowballs into a major expense.

Steve: When an NPDES permit is drafted by the Water Board, it’s subject to approval by EPA. In Southern California, the EPA has objected to draft NPDES permits because they didn’t include the new un-promulgated TST toxicity test method. The TST hasn’t been promulgated through the formal rule making process, the test is unreliable and generating false positives.

Essentially, the EPA has been pressuring the Water Board into adding the TST test requirements to permits, which we object to. As I mentioned, we’re challenging this legally on several fronts. The concerns are the impacts on the wastewater sector, it’s time, it’s money, and an unnecessary distraction from our core mission. There are a lot of resources dedicated to this issue right now with diminishing or no returns.

Another major concern is the SWRCB has drafted a statewide toxicity policy that includes the TST as a compliance test.

Lorien: The EPA has also objected to permits in Region 2, but the limits being imposed in recent permits use the IC25, not the TST. Things are different and inconsistent throughout the state. The EPA seems intent on limits everywhere, but they’re pushing the TST harder in different Regions.

How might new toxicity rules impact wastewater labs?

Steve: If false positives or positive results based on an extremely sensitive test are picked up by a citizen or news agency not familiar with the sensitivity of the test, we could erode public confidence in wastewater treatment systems. That’s a concern for us, especially as we move towards potable water reuse.

We’ve done independent studies and seen false positives range from 10% to 50%. The TST statistical method assumes the water is toxic. It’s guilty until proven innocent, which is different than normal assumptions. We’ve seen results as high as 50% false positive for toxicity. That’s quite a roll of the dice, especially with a new enforcement policy in place that increases fines.

Some labs had clean lab blank water turning up toxic. That’s alarming. Then they switched it around to another lab and the clean water turned up toxic again, while a sample with a known toxicant turned up with no toxicity. There’s a lot of variability in the test, and this is just the method of interpretation. This is mostly associated with the small water flea, Ceriodaphnia dubia. It’s really hard to keep them alive and have them reproduce even in laboratory conditions.

In contrast, the toxicity test we’re using now has a false positive rate below 5%.

Instead of putting all of our resources into toxicity testing, once the chemical is in the water, should we focus more resources on tighter EPA regulations and more public outreach to keep toxic chemicals out of water in the first place?

Steve: I would say YES! This is where all of our wastewater trade associations, CWEA, Bay Area Clean Water Agencies (BACWA), SCAP, California Association of Sanitation Agencies (CASA), Central Valley Clean Water Association (CVCWA), and the EPA should get together and do more public outreach. We should do more regulating of the sources. We should coordinate regulations with other wastewater groups, such as focusing on pesticide issues.

Lorien: I would add an emphatic YES to Steve. I would like to put in a plug for the Bay Area Pollution Prevention Group (BAPPG), which is a BACWA committee. We fund public outreach to reduce pollution that goes into the wastewater treatment plants. From wipes to pharmaceuticals we let people know what they shouldn’t flush and that “Toilets are not trash cans.” Through BAPPG we also fund regulatory advocacy on pesticides. Our consultant works with the California Department of Pesticide Regulation and EPA Office of Pesticides Programs, urging them to consider possible routes to sewers as part of pesticide risk assessments when they’re doing product registrations.

The other entity I’d like to mention is our Regional Monitoring Program through the San Francisco Estuary Institute. All wastewater treatment plants help fund research looking at pollutants in the San Francisco Bay. They do an assessment over which of the emerging contaminants are of increasing concern. For chemicals that may be of concern, we can then figure out how to control inputs to sewers where we can. Finally, California has a safer consumer products initiative where if we find a compound causing issues in the Bay, there is a process to eliminate it from products sold in the state.

Just imagine if the $3,000 we’re going to spend on each toxicity tests was redirected towards pollution prevention and science on emerging contaminants in receiving waters? Those funds would be put to a much better use.

Adam: I can add a third emphatic YES about the important role of source control. We are not able to control so many of the things coming into our system. It’s becoming more complex to identify them, to treat them, and so source control is increasingly important.

Steve: I’d like to add the cost for all this activity falls on rate-payers. Many of the people paying a wastewater bill may never use any of these pesticides or pharmaceuticals. They’re not getting any benefit from these products but they’ll be required to pay to remove the by-products as contaminants.

What can water professionals do to help on the topic?

Adam: The biggest thing folks can do is track this closely and get involved. Keep an eye on what the Water Board is doing. Weigh in with your thoughts. Provide information to statewide associations such as CASA and your Regional association such BACWA and SCAP. Tell us what’s going on in your lab. This will help us advocate for a better policy overall.

Lorien: I really appreciate the leadership CASA has shown. BACWA has participated in discussions with the Water Board alongside CASA, and of course BACWA will continue to bring its regional issues to the table alongside the statewide issues.

Steve: It’s important these regulations are practical and reliable. It’s one thing for large wastewater agencies to figure out how to comply, but this process is even more challenging for the smaller agencies. They have a smaller rate-payer base and fewer staff. We need to think about how those agencies will be impacted.  The more people involved, the greater our success will be.


Adam Link is the Director of Government Affairs for the California Association of Sanitation Agencies (CASA)
CASA is the leading voice for California’s public wastewater agencies on regulatory, legislative and legal issues. Adam leads a variety of initiatives for the association and regularly works with state and federal regulatory agencies as well as with members of the California Legislature on issues of importance to the water and wastewater community. Prior to joining CASA in 2013, Adam was a practicing attorney with the law firm of Somach, Simmons, & Dunn, focusing on water quality, environmental and local government issues.

Steve Jepsen, Executive Director – Southern California Alliance of Publicly Owned Treatment Works (SCAP)
Steve Jepsen  is the Executive Director for SCAP. Mr. Jepsen started a career in civil engineering consulting in 1981.  Prior to leading SCAP, Mr. Jepsen provided capital program management services for a variety of water/wastewater public agencies blurring the lines between public and private entities to expedite progress towards environmental and public health. Most of the projects he has been involved with have been wastewater, water and storm drain systems for public agencies in Southern California with emphasis on projects in environmentally sensitive areas, projects in dense urban areas and regulatory compliance driven water quality projects.

Mr. Jepsen has been an active member of SCAP and CWEA for decades. He is a past board member and president for the San Diego Section of the California Water Environment Association (CWEA).

Lorien Fono, Regulatory Program Manager, Bay Area Clean Water Agencies (BACWA)
Lorien Fono has been working with BACWA as Regulatory Program Manager for five years. She collaborates with BACWA’s member agencies to provide a Regional voice on wastewater issues when working with Regional, State, and Federal regulators. Lorien has worked as a wastewater consultant specializing in wastewater, recycled water, and stormwater regulatory compliance, water resources management, and wastewater planning.  Her background includes water quality research, focusing on the occurrence, fate, and transport of emerging wastewater-derived contaminants.

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