Paul Gagliardo is directing the city’s recycled-water research at a facility in San Pasqual Valley.
Two years ago, city officials announced plans to proceed with a radical new idea they had long toyed with: building a plant to make drinking water from raw sewage. As the news spread, protests began to rise on talk radio. Roger Hedgecock railed against the idea. Hundreds of callers denounced it, and many showed up to protest at two forums the city had arranged prior to the drafting of an environmental impact report.
City's hyacinth ponds. It turns out hyacinths don’t always thrive in sewer water.
While the commotion soon faded, most observers felt that the city council, embarrassed by the outcry, would not proceed further. But the project didn’t die. In the two years since the last public mention of the plan, it has grown larger, more expensive, and more certain.
Last month, in a 6-2 vote completely overlooked by local media, the city council approved spending another $10 million on engineering and design work, bringing the total investment of public funds on research and planning to roughly $40 million. According to city estimates, building the plant would cost at least $63 million, along with another $36.1 million for the pipeline that would carry the treated water to San Vicente reservoir near El Cajon. Insiders say the ultimate cost could be much more.
An internal city document, not for public consumption, shows that the council vote was right on schedule, the latest in a series of choreographed actions to pave the way for construction of the plant beginning in November 1999. By this July, at least five months before the project’s environmental impact report is set for public release, 30 percent of the project design is scheduled for completion, according to the document.
Scientific opponents of the plan claim it is an untested nightmare into which local, state, and federal officials are quietly pouring millions of tax dollars to see whether San Diegans eventually get sick and die from years of drinking treated sewage water. They point out that the city is still experimenting with treatment and monitoring techniques, including ultrafiltration devices, and still trying to demonstrate that the system is safe with only months before a final design is due to be made public.
Paul Gagliardo, who is directing the city’s recycled-water research at a small test facility in San Pasqual Valley, where the city has set up a complex maze of pipes, filters, and disinfection devices to test its plan, takes issue with critics who say that the proposal is dangerously half-formed and underresearched. So far, he says, an elaborate testing regime costing more than $10 million has shown that the project can produce safe drinking water at a reasonable cost.
“The question becomes does the data come out so that we can make a decision based on the data, and if it does, then we’re kind of home free,” Gagliardo says. “If the data comes out that it’s not clear that this is the direction, or this is the answer, then it may generate some additional cost. But at this point in time, our preliminary data is pretty good. We think we’ve got a real winner here.”
That position has been supported by the state’s Department of Health Services (DHS), which has been monitoring the project’s progress. In a letter to Mayor Susan Golding dated last October 25, health services division chief David Spath acknowledged that the project would be “the first planned indirect potable use of repurified water in the United States.” He went on to assert that the project, as then proposed, would “provide the highest level of public health protection and meet the most stringent reliability criteria to ensure that the citizens of San Diego receive a continuous supply of safe drinking water.”
Yet despite assurances to the contrary, internal state and city documents show that the eventual effect on public health of dumping millions of gallons of what was only a short time before raw sewage into Lake San Vicente, a drinking water reservoir in the hills near El Cajon, remains an open question. Raw sewage contains millions upon millions of toxic organisms, from viruses and bacteria to larger organisms like Cryptosporidium and giardia. According to the documents and interviews with state and local government workers, designing a foolproof scheme to detect and get rid of these and other hazardous organisms and chemicals,
many as yet unknown to science, has turned into an engineering horror.
An April 1996 memo, written by Spath to the city, points out some of the problems, including tests that “revealed that the RO (reverse osmosis) process removed a lower amount of viruses than expected, and that MF (micro filtration) may not be a consistently reliable virus barrier.” In
response to the criticism, the city has embarked on another round of testing.
The plan is experimental enough that Department of Health Services regulators have also urged that the city spend millions of dollars on what it calls a “Long Term Health Effect Monitoring Program,” including “public health surveillance” and “epidemiology,” to measure the
degree to which people drinking the water may get sick over the next 30 years. Adding to their fears, critics say, is the fact that much of the water will be consumed by elderly residents and patients in the hospital and medical research complex of Scripps Clinic and other facilities.
David Okun, the Kenan Professor of Environmental Science, Emeritus, at the
school of public health of the University of North Carolina at Chapel Hill, is one of the world’s foremost authorities on sewage water treatment and public health. If the plant is built, he fears outbreaks of illnesses.
“In the case of the project in San Diego, the current reservoir [contains] a fairly high quality of water. It drains a watershed that’s relatively little developed. And to purposely put wastewater into that doesn’t seem to me to be a great idea, considering the other alternatives.
“Just because we have the technology for it doesn’t mean it’s the right thing to do, in my opinion, because as with anything of this sort, we depend upon technology to protect us, and there are failures of technology. We’ve had outbreaks when we had all the equipment, and it was supposed to be run properly, but something happens and it wasn’t run properly, and there were problems.”
Okun points to the April 1993 outbreak of cryptosporid-iosis in Milwaukee. He notes it is difficult to test accurately for Cryptosporidium, a tiny sporelike organism that can cause illness and even death. “These are very, very difficult to identify in water. If there are 100 of these organisms present, we are lucky to find 5 or 10 of them. The monitoring becomes very expensive. You have to do a lot of samples. With pathogens as highly infective as these, where only a few cysts or oocysts may cause the disease, such monitoring data understate the risks.”
The city’s Gagliardo argues that Okun’s criticisms are ill-founded. He notes that other cities around the country, including Washington, D.C., and New Orleans, already rely on water derived from treated sewage. “Everybody discharges wastewater into whatever river is handy, and then the next town downstream takes that water out, so we’re in essence drinking treated wastewater; everybody’s drinking treated waste-water to some percentage,” says Gagliardo.
“The statistical guys like to say that if you drink the water in New Orleans, it’s been used on average 17 times before the Mississippi River gets to New Orleans. So we kind of do it already, we just don’t really see it. There’s at least 200 treated wastewater discharges into the Colorado River before we take it off, and the water comes down here, so we essentially do it already.”
Okun counters that San Diego is the first city in the world to propose voluntarily mixing treated waste and drinking water. “You have rivers like the Ohio River where people take water from upstream, where cities discharge their wastewater. Well, just because that has been done in the past doesn’t provide us with a license for doing it purposely. A decision was made to take water out of the Ohio River, let’s say a hundred years ago, or the lower Delaware a hundred years ago in Philadelphia. But that was done at a time when we didn’t have full knowledge of the consequences. We weren’t concerned with the organics in the water. We weren’t concerned with a lot of the diseases that are today being caused by water.”
Organic chemicals, says Okun, pose some of the biggest potential long-term dangers confronting would-be drinkers of treated sewage. The so-called organic molecules have complex backbones of carbon atoms to which are attached a variety of other atoms including chlorine and bromine. Many have been artificially made for use in industrial chemicals — which end up in city sewers. If ingested by humans over long periods of time, experts believe, even traces of the chemicals can have an unpredictable effect on health. Many have already been determined to cause cancer. The number of such new compounds, devised by industry and medicine, is proliferating wildly, Okun notes, and tests to measure their traces in sewer and drinking water do not exist.
“There are 83 contaminants now being regulated,” says Okun. “Most of them, I would say 80 percent of them, are synthetic organic chemicals. These are in trace concentrations. Now there are many more, and every year we find out that there are some others that we ought to be looking at. There’s a generally accepted idea in our field that only about 15 percent of organics that are present in the water supply have been recognized, let alone characterized for their health significance.
“So we are producing thousands and thousands of new chemicals. But we don’t spend the same kind of money on finding out whether these chemicals cause us problems. So we don’t know what a lot of these chemicals are doing.” Ironically, Okun adds, many of the treatment processes proposed for the San Diego plant would create new combinations of organic chemicals, so-called disinfection byproducts (dbps), that have cancer-producing potential.
Gagliardo says the city is aware of the potential for producing cancer-causing chemicals during treatment and is trying to develop ways to avoid the problem. “The dbps are only formed when you’ve got total organic carbon and you’re
chlorinating. So if we take disinfected tertiary effluent from the North City plant, and it’s disinfected with free chlorine, then we do have fairly high numbers. So we can’t take the water after it’s been disinfected at the North City plant.
“So either we take undisinfected tertiary effluent, or we’re going to try another experiment where we use combined chlorine, that we think will not form as many disinfection byproducts. The RO [reverse osmosis] systems will remove about 50 percent of those dbps, so that’s another experiment that came out of our discussions with the health department.
“If that plays out, then we have a way around that particular issue. But either we take it off before it’s chlorinated, or we use combined chlorine as a disinfection on the tertiary effluent, and then take it after chlorination, so we have two options to resolve that particular issue, and I don’t think it’s going to cause us any significant impact.”
George Tchobanoglous, a U.C. Davis civil engineering professor who has served as a paid consultant to San Diego’s sewer-recycling program, has acknowledged that “while great advances have been made in analytical methods to identify contaminants in water, only a small fraction of the contaminants present can be identified and their toxicology known. This situation has frustrated attempts to develop acceptable criteria for drinking water from highly contaminated sources.” Another issue to be dealt with, Gagliardo acknowledges, is the development of detection devices sensitive enough to monitor very low levels of viruses and other pathogens, measured in units called “log removals,” as the water moves through the treatment process. “The monitoring techniques aren’t as precise as they need to be to detect four, five, or six logs of removal of virus, that’s the problem,” notes Gagliardo, “and to do it online in real time is even more of a challenge.
“We think we have an idea; we’re developing that idea, we’re collecting the data to try to show the correlations. I’ll be presenting a paper at the AWWA [American Water Works Association] national conference in Atlanta in the middle of June that will talk about all these correlations and develop our theory a little bit It won’t be finalized, but we will be floating our concept in a paper I’m going to write for that conference.”
Many of Okun’s concerns are shared by staff members of the state Department of Health Services, few of whom want to be quoted. Although agency brass have soft-pedaled any problems associated with the sewage-recycling plan, staffers have privately raised questions about whether estrogen compounds, now widely in use in medicine, might be introduced into the drinking water supply through recycled sewage.
“For me that’s kind of an issue that nobody has really looked at in the wastewater industry,” says a staff member. “We have a lot of these hormonal-replacement therapies. What I don’t know is what happens to the hormones when they are ingested by people. We know that they react and they make certain organs do things in the body, but once they’ve served their function, are they broken down by the body? Or are they just passed through the body? And if they’re passed through the body, then they are going to end up in wastewater, and we have no idea what the fate of those compounds is in the wastewater.”
Another internal Health Services concern is the city’s plan to use the San Vicente reservoir as kind of a viral “killing ground.” Under current plans, the treated water would be piped into the lake, where it would remain for six months before being piped out into the city’s drinking water supply. Supposedly, exposure to the sun and other effects of weather would serve to break down any viruses or harmful chemicals that managed to make it through the treatment process.
But when the city was asked by Health Services staffers to come up with prior evidence of this theory that had been in published scientific literature, they ran into a dead end. “Little information on virus removal/inactivation in storage reservoirs is present in the literature,” a city consultant found in July of last year. That prompted concern at the Department of Health Services.
“The city’s memo did contain several articles and reports on virus die-off in sewage or wastewater lagoons
that seemed to support their position,” says Dr. Richard Sakaji, a staffer based at Health Services headquarters in Berkeley. “My comments back to them basically were, you know that’s pretty good, but there’s a fairly wide range of values here and, well, which of the numbers do we pick, and do we know how representative this is of this particular situation that we’re in? Because wastewater lagoons typically are much shallower than the drinking water reservoir that this water is going to go into.” Without previous data, Sakaji notes, the city is in a quandary, because actually testing its viral destruction theory in the reservoir would be problematic. “It’s possible they could do more research, the only problem is, I’m not sure how they would do that. Following viruses in the environment is not necessarily an easy thing, even when you use what they call an attenuated polio virus, for example, something that’s been inactivated, basically.
“You let it loose in the environment, and then you have dispersions and dilutions, and you couple that with the poor recoveries that you have associated with the analytical methods, and there’s a great deal of error associated with that, so I’m not sure how meaningful the data would be at that point.” As a result, adds Sakaji, “You could give the reservoir some [viral] removal credit, but you wouldn’t put as much credibility in it necessarily; it wouldn’t be as strong a barrier as, say, reverse osmosis.” Ironically, the city’s involvement in the sewage-to-drinking-water experiment grew out of a well-publicized but failed experiment to treat sewage by using hyacinths, aquatic plants that clog lakes and streams. Largely paid for by federal funds, the hyacinth experiment was begun more than 20 years ago by the city’s then-head of sewer and water utilities, Richard King.
“This was back in the early to late 70s — 72 I think was when he first started,” remembers Gagliardo. “Dick came up with this idea of minimally treating wastewater, running out to East County into a huge, what they called a ‘bio lake,’ and there it would stay in that aquatic environment two years or so, and then they would run reverse osmosis on that water and then distribute that into the drinking water system.
King’s plan to derive potable water from sewage, notes Gagliardo, was “way, way before his time. We’re looking at a full generation by the time we’re actually going to do something like this.” But regardless of how practical, King got federal officials to take an interest in his notion, and they showered the city with millions of dollars. “Through working with NASA, working with the federal government, working with the state government, they got started moving more and more toward doing some kind of a study. [King] was able to get some federal Clean Water grant monies, and that’s what generated the Mission Valley aquaculture plant.”
King’s premise was that hyacinths could be used to treat sewage to the point where it could be easily filtered for drinking. Raw sewage would be piped into pools of hyacinths, and the plants would remove it. Later, according to the scheme, the hyacinths were to be harvested and used for fertilizer or burned for energy. “The grant was named Total Resource Recovery,” says Gagliardo, “and the idea was that you could use everything, with nothing left to dispose of.”
Many experts, including Elmer Keen, an engineering professor at SDSU, were dubious. “It does the job,” he was quoted as saying at the time, “but it requires a lot of land. I think it will prove to be far more expensive than more [conventional] water-reclamation plants.” But grant money was available, and the city proceeded with King’s idea. The first testing basin, dubbed “Aqua I,” was built in Mission Valley, but the project’s size and ambitions, fueled by tax dollars, soon burgeoned.
“I’ve got some old photos of the first Aqua I, which was in swimming pools,” says Gagliardo. With further infusions of federal funds, the plant was later expanded to an 18-acre complex, called “Aqua II” and built along Interstate 8 near the stadium. In 1992, “Aqua III” was set up on a 35-acre site in the San Pasqual Valley. At each step, city officials claimed they were refining the concept to make it practical. They also claimed that the experimental treatment process, which was expanded to include a filtering process called reverse osmosis, could produce drinkable water.
The project’s cost, estimated to be more than $50 million over its life, was shared by the city and the federal government. “It ended up being around 56 percent federal grant funded, and there was some state grant money, and then about 40 percent funded by the city,” says Gagliardo.
For years, the city touted the project in the media as a revolutionary success that could become a solution to the area’s sewage-treatment problem. Despite the hype, and just as Keen and other critics had predicted, the experiment was a monumental failure, although until recently the city never admitted it. The hyacinths treated sewage all right, but only small volumes of it, and they required huge amounts of land, making the concept unrealistic for a city the size of San Diego.
“It works great,” Gagliardo says. “But you’ve got to have cheap labor, and you’ve got to have a lot of land, and that’s not really what we’ve got in Southern California.” Plus, it turns out hyacinths don’t always thrive in sewer water. “The plants don’t do that well in the winter. It gets a lot colder up here [in the San Pasqual Valley] than it does in Mission Valley, and in the winter time, they start crapping a little bit; they just make it through the winter and they stop growing so fast, and the treatment level isn’t as good as in the summer.” Next year, says Gagliardo, the hyacinths remaining at the San Pasqual facility will be torn out. “It’s really not cost-effective. For big systems, it just doesn’t make any sense.”
Although the project failed, Gagliardo says that the city’s research into the health effects of drinking treated sewage laid the groundwork for today’s sewage-into-drink-ing-water efforts. “What we were able to do with these studies was to show that you could reliably and safely recycle wastewater and reuse it,” he says. “All the health-effects studies that we’ve done on Aqua II water and on the Aqua III water have shown that when you look at all the parameters of the recycled water and then compare them to the imported drinking water and look at the relative risk between the two things, there’s no significant difference in the risks associated with drinking imported water or recycled water.
“That’s what’s allowed us to even ask the state health department, ‘Can we pursue a project like this repurification project?’ So all of that money spent, even though this [hyacinth] facility isn’t really cost-effective from a commercial standpoint, the research work that was done and the health-effects work that was done will allow us to beneficially reuse a lot more recycled water than we would otherwise be able to do.”
Critics, however, cite the city’s hyacinth fiasco as one more reason to question whether officials are being honest about the data at the San Pasqual plant. They also question whether the consultants and engineers hired to conduct the health-effects research have delivered unbiased information. The issue is critical, since the only data to support the city’s position comes from researchers hired by the city.
“In a comprehensive five-year investigation,” says a city brochure referring to the San Pasqual studies, “the City of San Diego Aquaculture II study concluded that health risks associated with the repurified supply were no greater than those posed by the current City of San Diego supply.”
That was the conclusion reached by a group calling itself the Western Consortium for Public Health, originally hired by the city in July 1985 to evaluate the health impacts of treated water generated by the hyacinth project. Western Consortium was paid a total of $3 million by the city.
The so-called purification plant would be built near the city’s tertiary treatment plant in University City. The theory is simple: take already-treated sewage water and put it through a series of high-tech filters and chemical treatments to kill or remove viruses and other bugs, then send it to a reservoir, where remaining microorganisms would be killed over time by exposure to natural elements like temperature and sunshine. Treated water would be piped to San Vicente reservoir, where it would be mixed with raw drinking water and, after a period of months, piped into the city7s drinking water system.
The city’s plans originally called for a series of four basic processing steps, beginning where the new North City water reclamation plant left off. That facility, set to become operational this summer, will produce treated sewage that officials say is clean enough to water lawns and wash cars, but still not fit for drinking.
Under the city’s initial proposal, first made public about three years ago, the effluent would be further processed by running the waste stream through a variety of filters, including microfilters, ultrafilters, and reverse osmosis filters to remove viruses, bacteria, gia-rdia, Cryptosporidia, as well as organic chemicals.
To assure a full kill of the microorganisms, large doses of chlorine and ozone would also be administered before the water would be piped to the San Vicente reservoir, where it would remain for a “stabilization period” designed to kill any organisms that remained, before being pumped into the city’s drinking water supply.
It was a version of this so-called treatment train that the city’s “health effects” consultant, Western Consortium for Public Health, said would produce safe drinking water, a claim the city has relied upon in its promotional literature and video for the project.
But late last year, confronted with soaring costs, officials began toying with ways to make the process cheaper, including dropping the addition of ozone and the introduction of a new generation of “ultra-low-pressure” reverse osmosis technology.
Those proposed changes have caused the state Department of Health Services, which had granted its “conceptual” approval, to take a second look at the project. “To obtain approval for changes in the treatment process, the City will have to demonstrate that the new treatment train will provide an equivalent degree of treatment as the [previously] approved treatment train in terms of effluent quality and system reliability,” according to a January memo from the Department of Health Services to the City. “The constituents of most concern include pathogens (giardia, Cryptosporidium, and viruses), disinfection byproducts, and nutrients. Based on available information, it is unlikely that the City will be able to demonstrate that chlorination of the tertiary effluent will be equivalent to the disinfection provided by ozone.”
The Department of Health Services memo goes on to say that the city “may be able to demonstrate that a combination of the proposed treatment changes such as chlorination of the tertiary effluent and use of ultrafiltration would be equivalent to disinfection provided by ozone.” But the document calls for more study of the issue.
The memo also shows that the agency remains concerned about the potential creation of unacceptable levels of dbps and whether the plant’s filtering membranes would be sufficient to remove them. “Short-term dbp testing may not adequately challenge the membranes, because it will not represent how the membranes will perform over time,” the memo says. “If the data indicates that dbp formation in the tertiary effluent will be a serious concern, then further studies may be necessary.” Yet another unanswered question is whether the disinfection byproducts will truly be destroyed during the time the water remains in San Vicente reservoir prior to being released into the drinking water supply.
The city has embarked on another round of new tests at its San Pasqual research center to answer some of the questions raised by Health Services. City documents show that the research topics include whether “giardia, crypto” is “excessive” in the city’s sewage effluent, and whether ultrafiltration, which uses filters with pores so small that even the tiniest viruses would theoretically not penetrate, could replace the use of ozone. According to a Health Services spokesperson, a city response to the agency’s January memo was expected to arrive in dhs offices this week
Gagliardo says that the city is responding to the Health Services concerns by “developing some additional pathogen challenge study protocols in order to, one, show that there is adequate disinfection across these various unit
processes, but also, Rick Sakaji, who is one of the DHS guys up in Berkeley, is requiring a fairly rigorous statistical analysis to be done, which means we have to collect more data than we had originally intended so we can do what they call a ‘Monte Carlo’ simulation on the distribution plots of the data points that we get for each unit pro-
cess. It’s way over my head from a statistical standpoint.
“So that’s what’s being negotiated at this point in time — exactly how much and what kind of data do we need to collect in order to massage the statistics. What Sakaji is calling it is ‘confidence testing.’ It’s a confidence analysis.
“It’s extremely elaborate.
It’s a matter of taking the data and analyzing the data from the standpoint of how repeat-able are the values that we get, how certain can we be that all this equipment will always work the way we expect it to work. What we’re doing now is trying to develop this monitoring technique, to try to show on-line, real time that the equipment is doing what it’s supposed to be doing.” Gagliardo estimates that the additional research will require “at least six months to a year’s worth of additional work that we’re going to be doing.” It won’t, however, delay the project, he says, unless the city decides it can’t comply with final conditions laid out by the Department of Health Services. “It becomes an issue of cost and reliability and manpower. The end result is, if too many of these things go against us, and if so many people and so much work needs to be done to show compliance with the permit, that might drive the cost-effectiveness of the project to hell.
“I mean, if they want us to probe each of the vessels every day, that’s way too much time and effort, we can’t do it. If they want us to do virus seeding on a full-scale system on a periodic basis, that may or may not be too much work for us to do. It may not be worth it.”
The current research program, Gagliardo adds, is “an effort to show, to provide some protection to the public health as well as keep our costs down. Those two things are always the driving factors: doing it the most efficient way to keep our costs down, but collecting the data that the Health Department requires us to collect to show that we’re protecting the public health. That’s the two-edged sword that I’m trying to walk on both sides of.”