By Janis Keating

Whether to meet a permit requirement for the National Pollutant Discharge Elimination System (NPDES) or to comply with state or local regulations, municipalities and private firms alike are constantly testing the waters. Just as their reasons for testing vary, so do their testing protocols. Some facilities take manual samples that are sent out for lab analysis; some use automatic samplers to compile data. Many use a combination of the two protocols, which appears to be the most accurate, cost-effective solution. Automatic data collection eliminates some man-hours and payroll costs while freeing workers for other tasks not easily performed by probes and machines. The result: easily obtainable water-quality data, which help solve water problems and aid in catching water-quality scofflaws.

A Clean Home for Fish

A remote monitoring system, complete with a solar panel battery charger

Setup of a portable monitoring system near a municipal storm sewer outfall

Along with wanting clean water sources for humans, Steve Fischer, a fisheries research biologist in Missouri's Department of Conservation, wants fish to have clean places to live.

"Two agencies are concerned with Missouri's stormwater and water quality," Fischer says. "The Department of Natural Resources regulates water quality, and the Department of Conservation got involved to monitor changes in aquatic health, the whole biological health of our streams. Our main concern is protecting waterways for sport fish, although the state does have some fish farms."

Fischer, who monitors waters statewide March through October, uses automated systems, as well as sampling, to gauge water quality. "We test for dissolved oxygen [DO] and suspended sediments—any change in a stream's hydrograph, especially in urban streams. We also test for turbidity, temperature, pH, nutrients, phosphorous, nitrogen, conductivity, and fecal coliform.

"We employ a variety of samplers, including the Hydrolab 4A datasonde, out in the streams. We build [polyvinyl chloride] cases and anchor them in the stream bottom. The 4As take readings every 20 minutes. We visit the sites once a week and download the data. The datasondes run for three-week intervals, then we'll bring them to the lab, clean out and recalibrate them, then put them back into the streams. We have 16 data stations in streams between Kansas City and St. Louis," he explains.

The automatic units monitor DO, pH, conductivity, turbidity, and temperature. Fischer manually takes water samples to lab to check for sediments, pH, fecal coliform, phosphorous, nitrogen, and ammonia. "Basically I do the ‘nutrient' part of it," he says, "and the Department of Natural Resources runs the samples for us."

Methods for finding the most accurate data are under review. "As for TSS [total suspended solids] versus SSC [suspended-sediment concentration] methodology, we're trying to develop numeric criteria in our standards, trying to look at the whole issue," Fischer says. "We want to find what will give us the easiest, more accurate measurement."

Some data offer Fischer immediate clues. "We often see changes in conductivity—a spike or a depression in it—which often means something's up. Some places like to discharge wastes on Friday afternoons, and with those conductivity trends, it's easy to see the changes and catch the polluters."

Once the data are complied, the Department of Conservation develops watershed management plans. "We take the info to our management and share it with cities and counties so they understand the impacts to their waterways. Our department doesn't give out tickets to polluters; [the Department of] Natural Resources does all the ticketing. We do investigations in concert with them and move our findings to their enforcement agency.

"Our department also works for education and prevention," Fischer notes. "We have a group of volunteers, the Stream Teams, who use our findings as educational tools to help citizens understand the needs of the fish and insect communities we have out there in the wild."

Checking Your Work

Stormwater Management Inc. of Portland, OR, develops stormwater treatment solutions for engineers, developers, and jurisdictional authorities. To gauge how well its systems work, the company includes monitors near its installations.

Stormwater Management's StormFilter, a passive, flow-through filtration system, consists of a concrete vault housing rechargeable cartridges filled with a variety of filter media. When stormwater passes through the cartridges, they trap particulates and adsorb such pollutants as dissolved metals, nutrients, and hydrocarbons. These cartridges are replaced annually or perhaps more frequently, depending on the sampling unit's results. 

"We conduct field studies here and in remote sites around the country," says Field Research Specialist John Pedrick. "We want to know how much performance the client is getting at the site. Although we've used other brands, we've narrowed our use to Isco 6700 automated samplers because the parts are interchangeable—both the controller head and the base that holds the sampler bottles."

Isco battery-operated samplers collect 24 individual samples in either 1-lit. or 500-ml bottles, based on flow and time. "The samplers are about the size of a beer keg," Pedrick explains. "They're run by a clocklike movement, and samples are taken by the parameters programmed into the movement, which can be set by flow rates, time periods, or a combination of both. We sample for TSS and total and dissolved metals. We don't sample for oil and grease."

One collector near North Carolina's Outer Banks has been running since last October. "Twelve-volt batteries charged by solar panels run the sampler, and the unit also has a rain gauge hooked up to it," Pedrick describes. "Both have modems, and we can get the data, sample times, and other information by phone lines. It's a great project management tool. We can oversee the equipment from here, then contract with local companies to collect the samples and take them to the lab. We can even turn the units on and off by phone."

Such field stations require shelter. "We install our samplers inside underground concrete vaults, where we can hang them from the ceiling with a harness; in other sites we install a plastic cover or shed. These places are dry between storm events, which gives us time to install them. We input the parameters for the samplers and the pacing rate at which a sample is taken. The flow probes also need to be calibrated. If we discover the stormwater site isn't getting optimal performance, we can change filter cartridges, or we could add another vault in areas that need monitoring, thereby satisfying the regulatory agencies."

In San Diego, CA, General Dynamics's NASSCO shipyard builds and repairs United States Navy vessels, and Stormwater Management not only sold the shipyard a system but also has been evaluating the site. "Last November we installed four Isco samplers with flow monitors and rain gauges. We install whatever works best for a site or facility," Pedrick explains. 

"We report the results to General Dynamics. We're also doing some toxicity studies there. For certain projects we report to the client; for others, we report to the local regulatory agencies.

 "We're gearing up to install four units for the state of Washington's Department of Ecology, one unit in Oregon, and others in California and New Jersey," Pedrick adds. "We also do a lot of oversight on projects we're not actually doing. Getting the equipment installed, and making it work, is always a challenge—sampling helps us know we've done it right."

Checking Quality, Meeting Permits, Testing BMPs

Dan Line, an Extension specialist for North Carolina State University, keeps tabs on the state's water for a variety of reasons.

"As a university, we get grants and contracts from the state or the US Department of Agriculture," he says. "We test our water as part of an overall water-quality program, to meet recent NPDES requirements, and also to test the BMPs [best management practices]. A number of the practices are new, so we're testing them."

Using a variety of Isco products—"6700s, 6712s, 700 modules, some old 3700s and refrigerated samplers too"—Line tests for nitrogen, phosphorous, sediment, fecal coliform, metals, surfactants, turbidity silt, pH, and polycyclic aromatic hydrocarbons. Most testing monitors stormwater runoff from roads, construction sites, and other land use.

"These are automated samplers. We check them once every two weeks, and of course after each storm event, we recover the samples," Line says. "Although I've been working on various projects for about 10 years, some of these projects are now two to three years old. We test at about 18 different sites, and our lab testing varies by project. We send samples to a state-certified lab to be analyzed. When I get the data back from them, I combine it with the flow data from the sampler, check to see how it's reducing the pollution loading."

Line explains his setups and procedures: "When I go to a site for a BMP, I set up all the monitoring. Sometimes there's a pipe or a ditch, and I put a weir across it to hold the equipment. At most of the sites—some sites are on streams, some are storm drains—there's nothing there when I set up the equipment. Before the Department of Transportation puts in the BMP, I tell them, ‘I need this and this for monitoring,' and they will accommodate it.

"I do manual samplings in the field, checking the equipment, especially when there's a problem, when it doesn't take a sample," he says. "When something looks suspicious, I take it into the lab. However, the samplers themselves have been very durable. Some I've been using all 10 years. The flow meters are not nearly as durable; after two to three years they need a pump change or service. Of course, testing is done all year-round, and freezing causes problems. The equipment depends on open channel flow. When you get ice, the equipment goes haywire. Fortunately we don't have much of a freezing problem—maybe overnight, but then the next day it thaws."

Garbage In, No Garbage Out

Roger Rardain, a lab analyst for Fairborn, OH's wastewater treatment plant, tests the waters coming in and going out of his plant with samplers from Yellow Springs Instruments (YSI).

"We test influent and effluent, using a YSI 5100 DO meter. We've also used the YSI 5905 and the newer 5010 DO probes, and we have an old 57 as a backup meter for BOD [biochemical oxygen demand] determinations," Rardain says, adding that most of the testing is for DO and BOD.

"Of course, you know water is never completely clean," he observes. "What's in it? Microorganisms use things for food, and BOD is like food; when the microorganisms are there, they suck up all the oxygen too. Now, some air and some food has to go into the river [where Fairborn's effluent eventually goes]. Distilled water, even 100% pure water, is not great for river life, and it would be expensive for us to produce anyway."

Fairborn also uses the YSI PC 600R multiparameter water-quality monitor in its effluent. "That monitors for temperature, DO, and pH in the final effluent, which we report to Ohio's EPA. We also use the YSI 3500 environmental process monitor to control the sequencing digester process. It turns aeration on and off."

Because he's dealing with domestic wastewater, Rardain tests for different pollutants than those who test stormwater. "We test the effluent for nitrates, phosphorus, and ammonium using a spectrophotometer and standard methods. To eliminate pathogens like fecal coliform, we disinfect with UV light, not chlorine, between May 1 and October 31. To check for that pathogen, we use the membrane fecal coliform technique—soak it on a pad in a broth, place it into an incubator, and look for growth. Of course, federal regulations outline what testing processes one can use. We use those that produce the most reliable results."

Watching the Watersheds

As her department is responsible for watershed protection, Jo Ann Weber, supervising environmental health specialist in the County of San Diego's Department of Public Works, field-tests for possible pollutants.

"We're looking for nonpoint-source pollution. Our Dry Weather Program has two main responsibilities: detecting and eliminating illegal connections and discharges [IC/IDs] to the county's MS4 [municipal separate storm sewer system] and characterizing water-quality conditions in the unincorporated part of the County of San Diego," Weber says. "Much of our stormwater flows through natural creeks, although some of those have been enhanced with concrete. We're under a Phase I NPDES permit, so we're required to do water testing, and some tests we do voluntarily." 

The County of San Diego's testing occurs between May 1 and September 30, the area's dry season, when it's easier to trace a discharge from an illegal source. Weber's crews, which monitor 80 locations three times a season, test for ammonia, nitrates, and phosphates using field test kits. Once a year, water samples are collected to be analyzed in the analytical laboratory for total and fecal coliforms; enterococcus; oil and grease; the organophosphate pesticides of chlorpyrifos and diazinon; methylene blue activated substances (MBAS), a test for detergents; and trace metals. Electrical conductivity, pH, DO, turbidity, and temperature are also checked using a multiparameter probe, which provides real-time data in the field. "About half the time, we check for zinc and MBAS," Weber explains. "We're not required to test for zinc or MBAS in the field, but we think it helps us."

Field testing combines analytical testing and visual observation, which is aided by field test kits. "We use a photometer, which gives a digital reading, instead of color wheels, which eliminates field staff having to make color determination judgments." Photometers such as those manufactured by CHEMetrics can test for multiple analytes on-site using different modules for each.

"Our portable sampling kits are smaller than a lunchbox, easy to carry," Weber notes. "It takes about 25 to 30 minutes to use the kits. We're looking for qualitative data, an indication if constituent is present or absent. We can take about 30 samples before having to replenish the kit."

There are some drawbacks to field sampling kits. "You may get interferences, which can result in a false positive, especially with ammonia, phenols, and copper. However, the kits' manufacturers are good at giving you a list of interfering constituents, and they help if you still have a problem. We did dilutions to test and find the interference; there was also a precipitate, which indicated interference. Last year we changed our ammonia testing kit, and it helped. Some interferences may occur because water contains high TDS [total dissolved solids]. We also have an ongoing quality-control program for our kits. We'll do side-by-side testing—test in the field, split the sample, send that to the lab, then compare the results. It's a more efficient use of the staff's time to use a kit we have confidence in."

Once the data are collected, Weber's department uses written guidelines or "action levels" to indicate when her crews must shift their duties from sampling to investigation. "Let's say we find a sample in which nitrates seem a little high. We then go upstream and look for the source. We can often trace the flow; we'll see an outfall, test there, but may have to go higher upstream to find the source. We will also look for the discharge, even if it's in the street, take tests, and then give our results to the compliance staff," she says.

Thirty-five of the county's 80 stations were investigated last year for action levels. Weber offers a few examples of her department's investigative work. "During field testing, we found high nitrates, ammonia, and bacteria levels at one of our stations. We traced the source back to an apartment complex. We sent official notice to the complex to stop the discharge. They traced it to a leak in their underground irrigation system, which was dug up and fixed.

"In another instance, we measured elevated nitrate levels and began an IC/ID investigation. We found several commercial nurseries discharging irrigation overflow to local creeks, which may have contributed to elevated nitrate levels. The nurseries were referred to the county's compliance and enforcement staff. During joint stormwater inspections of these nurseries with San Diego's Regional Water Quality Control Board staff, these discharges were eliminated," Weber recounts.

Some pollutants come from "natural" sources: "We will see some bacteria sources, sometimes from wild bird feces—gulls, for example. We have also found high dissolved solids [conductivity] and discovered they were likely due to natural groundwater interacting with bedrock. We found surface seeps on streambanks, in which groundwater was being discharged to the stream. But TDS in water is not always due to natural sources. For example, our drinking water, which is imported hard water, may contribute to our TDS levels."

The County of San Diego's testing program, which has been in place since the early 1990s, is run in cooperation with other area agencies. "‘Action levels' vary from jurisdiction to jurisdiction; we have a dry-weather work group that works in cooperation with co-permittees and neighboring areas, sharing information and experiences. It's a useful forum," Weber states. "Often at some locations, a neighboring city's conveyance system may empty into ours, and vice versa. If something is found, we will provide the data to the other jurisdiction to conduct their own source investigation."

Although most of Weber's staff mainly focuses on detection, a certain amount of attention is paid to prevention. "We use outreach as well as enforcement. We want to increase awareness of urban runoff issues. We use education first because we ultimately want to change behaviors. We provide copies of our water protection ordinance so people are aware; enforcement is the last resort."

Janis Keating is a frequent contributor to Forester Media publications.

SW - July/August 2003

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