Stormwater Programs in the Arid Southwest

Challenges of rainfall patterns and public perception

It rarely rains in the arid Southwest, but when it rains … it pours.

That is the foundation of the challenge inherent in creating stormwater management programs and instituting effective public education outreach in the region.

“There’s a wide range of climates in North America, and the idea that you can write one set of regulations and have them apply to everybody is just tough,” says Lisa Spahr, a senior project manager for Engineering and Environmental Consulting in Phoenix, AZ.

Consequently, Arizona officials take a multifaceted approach to creating effective stormwater programs. The state’s primary concerns center on public education, responding to rapid growth, flood control, and water harvesting and recycling.

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Arizona has 68 water bodies and stream segments listed as impaired, for 129 pollutants, based on a 2004 305(b) report and 303(d) list. Total maximum daily load (TMDL) development and data gathering is accomplished with state and federal funding. The funding is not tied into municipal stormwater permits, but the state utilizes data collected by permittees if it’s credible, notes Jason Sutter, TMDL unit supervisor for the Arizona Department of Environmental Quality (ADEQ).

Convincing the Public to Care
It can be somewhat of a challenge to convince residents of an arid region that stormwater management should be a priority.

“People might ask, “˜If it doesn’t rain very often in Arizona, why should we be concerned about stormwater?'” says Stan Snitzer, the Stormwater Quality Program coordinator for Maricopa County, AZ. “I’ve often said, “˜Let’s assume it doesn’t rain for 364 days, and then on that one day, you get a chance to flush away all those pollutants you’ve stacked up out the back door.’ Rainfall in Arizona sometimes is gentle but often comes with some intensity. We might end up with an inch to 3 inches an hour,” he says.

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In the arid Southwest, “The time materials have to accumulate on surfaces is higher,” Spahr points out. “If there is an area where cars are traveling, leaving drips of gasoline, oil, and lead from exhaust, it builds up longer, so the first flush in the stormwater event tends to be much more contaminated here than it is in other parts of the country.”

To that end, public outreach–one of the six minimum control measures of Phase II of the National Pollutant Discharge Elimination System (NPDES)—becomes a key factor.

At StormCon ’07 in Phoenix in August, Spahr will be presenting “Life Might Be a Highway, but Nobody Really Lives There: A Public Outreach for the Arizona DOT.” Her co-presenter will be Stephanie Brown, Adopt-A-Highway project manager for the ADOT.

“Arizona Department of Transportation is regulated like a municipal separate storm sewer system [MS4] because they have storm sewers on their highway,” Spahr points out. “But unlike most MS4s, which are municipalities or counties, they don’t have residents. So while Tempe [Arizona] or Phoenix can do public outreach by sending notices in utility bills or distribute community newsletters in which they can make announcements, the Arizona Department of Transportation didn’t have any way to reach its users.”

Yet the need exists: People throw trash out of their car onto the road, and trucks travel without cargo properly fastened down. “As far as ADOT is concerned, a lot of the users of the highways care about that because it’s litter, it’s unattractive, and it’s also dangerous–especially stuff on the back of trucks,” says Spahr.

And while the department has a phone number for reporting those events, highway signs had essentially been its sole means of communication. “They can’t put information on highway signs that people need to stop and write down; that’s just not good to do on the highway,” says Spahr.

Engineering and Environmental Consulting’s first task for the ADOT was to determine what other MS4s in the area were doing. The firm found that the Arizona cities of Tucson, Phoenix, and Flagstaff had either formal or ad-hoc groups of all of the MS4s in their regions that accomplished regional stormwater outreach by pooling resources. The MS4s in each group all had the same radio audience, so if one municipality put an ad on the radio, everyone in the region would hear it. The municipalities pooled their money for radio commercials.

“Tucson also put stormwater education and outreach information on buses and bus stops,” Spahr says. “A lot of them also have Web sites where people can get education. It is a way to make more effective use of outreach.”

While it was apparent that municipalities have the bases covered, the ADOT was interested in other people on the highways and throughout the state who weren’t being reached by their educational efforts.

When Spahr’s firm realized that a cooperative extension agent from an area land grant university served on a Flagstaff stormwater working group, the connection between that person’s job in preventing soil erosion and managing pollutants in the watershed and stormwater education became apparent.

ADOT officials met with the coordinator of the state’s watershed stewardship program, which conducts a master watershed stewardship education program akin to the county extension’s Master Gardener program whereby one takes classes and becomes a master watershed steward, qualified to engage in volunteer projects and other activities.

“ADOT is going to be getting some of their employees to help teach parts of that program and provide support when they do outreach and education projects in schools,” says Spahr. “That turned out to be a way to reach every county in Arizona, because every county has a county cooperative agent and a master watershed stewardship program.”

The ADOT’s largest public outreach and education program comes through the Adopt-a-Highway program. “People see people on the side of the road picking up trash, and every section of highway is the responsibility of a particular group,” Spahr says. A sign on the side of the road indicates the name of the group that adopted that section of highway. Groups that do the best job of keeping the highways clean are given incentives, such as free baseball tickets and recognition during the seventh-inning stretch of baseball games.

The ADOT also supported the efforts of a Tucson stormwater working group that conducted an outreach education seminar for the construction industry by putting together some of the manuals. “They have a manual on soil erosion that many people all over the state use as a reference tool for doing stormwater maintenance,” says Spahr. “They made copies of that document on CDs and gave it to everyone who went to that training for free. ADOT has a budget for that and they support regional efforts where they can and where they are needed.”

Cooperative efforts among government entities in the public education realm have been a “major success,” says Snitzer, citing the work that’s been accomplished through Stormwater Outreach for Regional Municipalities (STORM).

The nonprofit regional organization promotes stormwater-quality education in the Phoenix metropolitan area. Founded in 2002, the effort enables numerous municipalities to pool limited resources in an effort to provide a regionalized response to federal regulations requiring public education on stormwater issues.

STORM utilizes a multimedia approach of radio, TV, and movie theater spots as well as a Web site. The site touts a catchy phrase, “Only Rain in the Storm Drain,” that concisely encompasses the message.

A public service radio announcement reached 1.5 million people in the region in both English and Spanish during December 2006 and January 2007. The radio spot encouraged area residents to take measures to reduce the discharges of pollutants from their properties. “As individual cities or as a county, we probably would not have had the budget to approach that, whereas by combining resources, we were able to achieve that,” Snitzer says.

STORM participants also have developed educational materials and spoken with state legislators about the county municipalities’ stormwater programs.

“It’s challenging in that it doesn’t rain often and we’re often not aware of what impact our own activities may have on water quality,” Snitzer says of the challenge of public education about stormwater. “That’s the importance of getting an educational program to inform the public of good practices and reducing contaminant flows. We have an ongoing availability of pamphlets from various city organizations. “We have no idea who may pick up a pamphlet–it could be a homeowner, a schoolchild getting a book, someone involved in the construction industry. We’re hoping to reach a wide gamut of people with this information.

“We’re hoping in future surveys that we will find continuing improvement in the recognition by the citizens and residents of our metropolitan area and Maricopa County and improving awareness in the part they can play in reducing pollutants.”

But education begins at home.

As for the NPDES minimum control of good housekeeping for municipal operations, Snitzer says, “When we look at our own operations, we realize we could do a better job educating our Maricopa County staff, so we have begun a process of education within the staff to let them know about these good housekeeping prevention measures.”

Public education efforts often involve pointing out the obvious.

“We tell people if they have a vehicle that is leaking, they need to do maintenance or put an oil pan underneath it if it is leaking,” Spahr says. “We tell people not to top off their tanks at the fueling stations because those last couple of drops as they are putting the nozzle back into the pump go into the ground and can get washed away.”

Another approach Spahr suggests is the placement of ramadas over areas where contaminants can accumulate on the ground so rain doesn’t hit that part of the ground, washing away the contaminants.

A Countywide Challenge
Perhaps no area in Arizona represents the challenges of managing stormwater in the arid Southwest better than Maricopa County, one of the fastest-growing counties in the United States.

“We’re about the fifth-largest county in the United States, and we have seen very little slowing in the rate of growth here,” Snitzer says. That creates a challenge in keeping up with the demand for regulatory inspections of construction sites.

“We had forecasted five years ago possible downturns in construction, but they never did occur,” Snitzer says. “Maricopa County continued to increase the number of building applications we processed. Our planning and development department covering just the unincorporated areas of Maricopa County receives about 16,000 building permit applications annually. Of particular concern for the small MS4-designated regulated areas of Maricopa County is that, by early examination of the database, it appears we have about 6,000 of those applications for areas of 1 to 5 acres in the small MS4 designation for the final rule.

“Arizona as a whole is growing, and many other counties in the state are experiencing rapid growth: Yavapai, Panal, Coconino, Pima, and Yuma counties are regulated counties, and yet we look at some of the other counties now in which growth is occurring rapidly and assume that in the next decade or two they will also be designated at least as small MS4s.”

Maricopa County applied for its NPDES permit in March 2003, but there has been no action upon the application by the ADEQ. “We’ve had meetings with them and hope to see that condition changing in the near future as we are approaching our need to prepare our documents for the next phase required of the small MS4s beginning in 2008,” Snitzer says.

The county recently wrapped up a year of rewriting its drainage policies and design manual through a joint effort by several county departments, including flood control, transportation, environmental, and planning and development.

“We’ve designed what I believe is something that could be turned into an actual policy for the county, helping us meet the post-construction requirements of NPDES Phase II whereby we design things that maintain the first flush of water,” says Snitzer. “We maintain that first flush on property. That would also mean the sediment that we might see flowing out if we didn’t have this policy would be maintained for the most part on the property. That’s a much greener approach than having no design factor whatsoever to maintain first flush waters on properties.”

Maricopa County’s examination of post-construction efforts focuses on a refined definition of policies dealing with the design factors on construction sites. The policy was expected to be approved earlier this year by the county’s board of supervisors.

“When you get done, you’ll leave in place a device to cause less runoff and more retention, and in that, it would reduce the possibility that contaminants would be flowing off property and more likely remain on property,” Snitzer says.

Snitzer points out the advent of silt fencing now being used in Maricopa County during pre-construction or construction. “We had not seen that much of it heretofore, but many of our cities are now requiring it in their ordinances,” he says. “There also are many more applications of drag-out prevention devices. They help reduce the drag-out of soils on building construction equipment going on- and offsite, especially coming offsite where the soil’s been disturbed.”

For example, tires might be carrying soils, which can be forced out of the tire grooves by rock beds and remain onsite rather than being tracked onto a paved street, where it might also contribute to dust and air-quality problems, Snitzer points out.

Managing Inspections and BMPs
In a state with such rapid construction development as Arizona, one key issue is keeping up with inspections. Spahr says one of the ways in which the ADEQ is trying to keep pace with inspections is in the MS4 permits given to municipalities.

“They want the cities and counties to be the enforcement arms and have been trying to require that counties conduct inspections of construction sites and of anyone who has an industrial stormwater permit or is covered under the Multisector General Permit,” Spahr says.

That’s become a big point of contention, she says. “The cities say they’ll take care of their own facilities, but they don’t want to do ADEQ’s job by inspecting industrial sites. They don’t see themselves as an enforcement arm of the state or the EPA. The inspection question is quite a concern.”

Figuring out which best management practices (BMPs) to apply in the arid Southwest is another challenge for state officials.

At StormCon ’07, Spahr will present “It Doesn’t Rain Much, but It Rains Real Hard: Construction BMPs in the Arid Southwest” with E. LeRoy Brady, chief landscape architect and manager for the Arizona Department of Transportation. The talk addresses the issue that there are important differences among climate, soil, and rainfall throughout the United States, especially in the time frame between storm events.

Spahr says the biggest issue in the region with construction stormwater prevention is temporary stabilization. “If you can plan an entire project that involves disturbing undisturbed desert land to occur in the dry parts of the year so that there will be no rainfall from the time it starts until everything is in final stabilization, that’s good,” she says. “But that hardly ever happens.”

The rainy season is generally during the winter months of December through February, and monsoons can start in the beginning of July and last through September. Construction is best done in October and November as well as March through June.

While the least expensive form of temporary stabilization is seeding, Spahr points out that is not an effective method in the arid Southwest.

“It would require a lot of irrigation,” she explains. “Other available methods include different types of geotextile fabrics, but that is much more expensive than it is for people in the eastern United States who throw some grass seed and water on it and know it will grow in two or three days.”

Spahr says the current rule is if an area is going to be disturbed yet not worked on for two weeks, temporary stabilization is needed. “We can’t get anything to grow in two weeks,” she says. “We say if you’re not ready to work on an area, don’t disturb it. If you disturb it, put in place what will be your final stabilization as soon as possible.”

That philosophy can be difficult to carry out for engineers who believe the most efficient approach is to bulldoze the entire area and work on a piece at a time. “You don’t really want to do that–then the whole site is subject to erosion, and you have to have some sort of temporary stabilization in place,” Spahr says. “A lot of it comes down to planning the approach and how you phase it. That’s the most cost-effective approach at this point.”

Another issue with which Arizona officials wrestle is flood control. The characteristics of rainfall in Arizona–a dry spell punctuated by an intense rainfall–often result in flash flooding.

“Our dry rivers will run,” says Snitzer. “We’ve controlled our water resources for flood control and irrigation purposes.”

With flood control, Spahr says there’s a general belief in the region that stormwater should not leave a site. “Every time a piece of land is developed, it is almost always increasing the impermeable surfaces,” she says. “You take a piece of desert, put a building and a parking lot on it, and soon 75% of the site is either building footprint or parking lot and only 25% is left to get rid of stormwater.”

One approach is to create a retention basin to slow down the water. “But they can be public hazards if they get too deep or muddy and kids go in them and get stuck in the mud or drown,” she notes, adding they take up a lot of land and for that reason are not highly favored.

Dry wells are another common practice in the area. “They are just a hole in the ground where the stormwater percolates down to the groundwater,” she says. “But dry wells need an aquifer protection permit from the state. If that dry well is receiving any flow from anywhere—like a fueling gas station, a maintenance area, or anywhere where vehicles are worked on or equipment is fueled—then it has to have certain BMPs put in place around it to keep the gasoline and the fuels from entering the aquifer.”

Because a fuel spill can go directly to the dry well, often a magnetic cover has to be placed over the top of a well to direct any spills into a depressed area surrounding the dry well for cleanup. The cover is removed during a storm so runoff can enter the well. Filters are also sometimes placed in dry wells.

Spahr says many times when her company visits a site with dry wells, the wells have not been permitted and are not on the record books. Often, it’s because they were installed several decades ago when permitting wasn’t required.

“We do a good bit of business closing out dry wells,” Spahr says. “To close them out, you have to put three borings in around them and sample the sediment from inside the dry well. Every solution has its own associated issues.”

Rainwater Harvesting
One stormwater management approach that’s taking hold is water harvesting.

Ann Audrey is the environmental projects coordinator for Tucson, AZ’s Office of Conservation and Sustainable Development. She is coauthor of a paper to be presented at StormCon titled “City of Tucson Water Harvesting Guidance Manual: A Multifunctional Tool for Addressing Stormwater Quality, Stormwater Volume, Water Conservation, and Landscape Irrigation.” She defines water harvesting as beneficially retaining rainwater in multiple small catchment locations and using it to support vegetation.

“From the stormwater prospective, rainwater harvesting is a best management practice for sequestering contaminants carried by rainfall runoff. If you harvest this water at a site, then it sequesters these things in the soil, and to the extent that soil microbes get involved, there’s a bioremediation process that happens,” Audrey says.

Addressing stormwater-quality discharge issues was part of Tucson’s impetus to develop the water harvesting guidance manual, she says. “The other part of the stormwater picture is in terms of peak flow management, and retention and detention basins also accomplish this at sites, but water harvesting can assist with that as well.”

The least expensive way to harvest rainwater is to use small earthen basins, containing plants and located throughout the site, into which water infiltrates.

“We have structured the manual to allow multiple uses for rainwater harvesting areas,” says Audrey. “If you have a landscape buffer requirement, you can harvest rainwater in it. If you have a detention basin requirement, you can put plants in it and size it accordingly, because plants displace some of that water. If you need to put trees in a parking lot, you can make those depressed basins and harvest water there as well.”

Audrey points out a benefit to developers is that as they harvest water in the structures around the site, they can downsize the detention basin accordingly.

“You have less surface ejecting water in the first place, and if you depress them in a certain way, you reduce the amount of runoff going to the basin even more,” Audrey says. “That’s a particular benefit for commercial sites, because they might be able to get some more parking spaces because they don’t have to have such a big basin.”

Additionally, developers can combine detention basin requirements with the landscape buffer so the buffer can be part of the detention basin, Audrey points out.

“Site developers are interested in this approach, and once they see how it can benefit them, they are oftentimes glad to get this guidance and be able to sit down with our staff and brainstorm a site. It gets to be a creative process that’s fun for us and beneficial for them.”

Stormwater in the arid Southwest is “certainly a different critter,” Audrey acknowledges.

“We have gentle rains in the winter but aggressive rainfalls and isolated thunderstorms in the summer, so we get a couple of inches of rain in half an hour in some cases,” she says. “Our water harvesting structures always need to be designed to allow for runoff; you can’t turn off the clouds.”

A site is ideally designed so runoff out of a basin is directed toward an area where it can be beneficially used multiple times before it gets ejected from the site.

Water quality plays a major role in stormwater management efforts, Audrey notes. “That first flush of water that leaves the site–a quarter- or half-inch–particularly after a long period of no rainfall is carrying a lot of contaminants, so the ability to retain that at a site is definitely beneficial down the line in terms of keeping some of that typical urban pollution out of the waters of the United States,” she says.

Audrey favors a multifunction approach to stormwater management. “You improve water quality and help attenuate flood peaks, but we also can use water harvesting to conserve water in the arid Southwest, because if you water your landscape with rainwater, you don’t have to pump groundwater for irrigation.

“Water conservation is super important to us right now,” she adds. “Another aspect of it is the locations chosen for basins and what is grown in them; they can be used to do things like attenuate the “˜heat island’ effect, to shade buildings and reduce energy consumption, which in turn saves more water.

“Having an integrated design approach to this technique–which is beneficial to the city from the stormwater management perspective–also provides a lot of other benefits. Optimizing those is a great way to create a more sustainable urban design.”

Maricopa County normally has water recycling built into its design requirements, Snitzer notes. For example, subdivisions can get a credit for recycled water through the state’s Groundwater Management Act.

“Conservation and recycling of water is a very important part of all practices now in what we call the active management areas controlled under the auspices of the Groundwater Management Act,” Snitzer says. “There is concern of development in other areas to cause water management to occur in those areas as well now because Arizona is a very fast-growing state.”

Questions of Authority
Against the backdrop of public education, responding to development, controlling flooding, and water harvesting is the issue of which government agency an entity is responsible to. Although NPDES is a federal regulatory program, states have primacy to pass and enforce their own rules. Those who need a stormwater permit need to apply to the states in most cases.

In December 2002, Arizona became one of 45 states authorized by the EPA to operate NPDES on the state level, thus creating the Arizona Pollutant Discharge Elimination System (AZPDES).

“The AZPDES program did not consider endangered species whenever they gave permits, and the requirement in the Endangered Species Act [ESA] says every federal permitting action has to consider endangered species,” Spahr says.

In November 2004, the Defenders of Wildlife filed an ESA and Administrative Procedure Act suit in district court against the state. Spahr says the issue has become the state’s “800-pound gorilla.

“Arizona’s defense was if you look in the federal regulations for NPDES, it says in order for a state to get primacy for the regulation, they have to satisfy certain conditions, and those conditions did not list the Endangered Species Act,” Spahr explains. “Defenders of Wildlife’s point of view was it doesn’t matter, because the ESA says you always have to consider it whether the rules say you do or not.”

The issue is now slated for a US Supreme Court decision. Spahr says earlier legal decisions have favored the Defenders of Wildlife’s position that the Congress-passed ESA must be considered in any federal permitting and NPDES fits the requirement.

“EPA filed several friend-of-the-court briefs on the side of Arizona, because 46 states and territories have primacies for NPDES and if Arizona’s wasn’t legitimate, nobody else’s would be either,” Spahr says. “Suddenly, the EPA would have 46 states’ worth of people applying for permits, and they just don’t have the personnel to take that all back at this point.”

Spahr says some Arizona industries’ officials feel strongly that the EPA is more reasonable than the ADEQ on stormwater permits. “The original law written in the state of Arizona said none of their stormwater regulations can be more strict than the federal rule. There have been different ADEQ administrators who have interpreted that differently,” she notes.

Arizona has instituted an expedited program for stormwater permitting, and in order to stay on schedule, the state has hired private consultants such as Engineering and Environmental Consulting to help write the permits. The company does that as well as help write plans that are part of the permits.

Ultimately, it’s not such a stretch to convince Arizona residents to get serious about stormwater, although they live in an arid region, Spahr contends.

She tells of the time she lived in the Northeast and would tell people what she did for a living–“I’m a hydrogeologist”–to which they’d respond, “What’s that?” or roll their eyes.

“When I moved to Tucson, I didn’t have to explain what I did. People would ask me questions about groundwater, surface water, and water quality, because it’s in the news all the time in this state.

“We understand there are more people moving here and we have a finite amount of water. It doesn’t rain much here and we don’t have a lot of water bodies, but because of that, we are all really concerned about water.” SW_bug_web


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