WATER polluter OR WATER filter?
The question is hotly debated; the answers can be as clear as mud.
The question is hotly debated; the answers can be as clear as mud.
What happens to rainwater after a storm probably is not something you spend much time thinking about. But that apparently trivial question is at the center of a brewing regulatory controversy. So take a moment. Where does it go? Some of it soaks into the ground. Some of it evaporates back into the atmosphere as surfaces dry out. And some of it runs off, ending up in streams and lakes, perhaps via storm sewers. This water holds residues from all the surfaces it has touched — roofs, roads, parking lots, fields, landscapes. And that's why the Environmental Protection Agency (EPA) considers it pollution. Non-point-source pollution.
The substances that comprise non-point-source pollution (NPSP) include a wide range of materials such as solvents, detergents, pesticides, fertilizers, petroleum products and other materials, such as silt and ice-melt chemicals. Imagine all the oil, gas, rubber, coolant and grease deposited on roads by vehicles — that's NPSP. Imagine all the household products and used motor oil that get dumped down storm drains because people don't know how else to dispose of them — or just don't care. That's NPSP too. Even leaves sitting in the gutter are considered contributors to NPSP (because as they decompose, they raise nutrient levels in water).
Many experts feel the most important problems stemming from NPSP are those related to nutrient loading — a rise in nutrient levels such as nitrogen and, especially, phosphorus — that causes explosive growth in aquatic vegetation and so-called algal blooms. The resulting ecological disruption can be severe, say ecologists.
Enter the Clean Water Act, the EPA and Total Maximum Daily Load, or TMDL. The Fertilizer Institute defines TMDL as “the amount of a given substance or pollutant that can be allowed to enter a body of water, like a stream or river, without causing that body of water to exceed its water quality standards.” To combat NPSP, the EPA is enforcing compliance with its TMDL requirements, which say that states must take action to reduce NPSP in waterways that exceed EPA-established standards for various pollutants.
And this is where it gets knotty. Determining that water is polluted is a lot easier than determining where the pollution comes from and what to do about it. The goal of TMDL regulations is to reduce overall pollutant levels below established thresholds; but many fear that among industries that could be regulated, there will be winners and losers according to who has more clout.
The legislative history leading to the present situation is long and complex, but its origins date back to the Clean Water Act of 1972 (CWA). Despite some Congressional opposition, the EPA moved to implement TMDL regulations in July 2000. In response, Congress blocked implementation by eliminating needed funding. However, in one of President Clinton's famous last-minute actions, TMDL regulations were given the go-ahead by executive order. At this writing, the new TMDL rules still are scheduled to go into effect October 1, 2001.
TMDL regulations will require states, territories and tribes to develop comprehensive lists of water bodies that do not meet water-quality standards established by the EPA for listed pollutants. State government agencies must then take action to bring waters into compliance, either through voluntary programs or mandatory regulations.
For example, let's say the level of phosphorus (P) in a certain lake is exceeding the established limit, and it's determined that a reduction of some amount entering the lake through surface runoff will bring it in line with regulations. It will then be up to the state and local regulatory agencies that have jurisdiction to devise a plan to do so, by trying to determine where the excess P is coming from and how to reduce levels.
Devising fair and realistic plans will be difficult. But one thing is not in doubt — turf care is in the crosshairs.
Lawn care: the usual suspect
Turf management is frequently blamed for non-point-source pollution because turf fertilizers typically contain substantial amounts of nitrogen and phosphorus, the two most-implicated nutrients in water-quality problems. These nutrients, especially phosphorus, are often the limiting factor for algae and aquatic weeds in natural habitats. A large increase may cause excessive growth in surface waters. However, the question of whether turf care is responsible for all that is alleged is debatable.
P binds strongly with numerous organic and mineral constituents in the soil profile and exhibits relatively low solubility in water. So how does P enter waterways? By transport of sediment, i.e., erosion. As erosion carries soil particles to storm-water drains, streams or lakes, P (bound to the soil particles) is carried with it.
Erosion is usually insignificant in healthy grass stands established on good soil. If you correctly apply P fertilizer to dense, well-maintained turfgrass, P loss via runoff will be negligible. This is solidly supported by university research.
But critics call this viewpoint unrealistic. Most turf is not in such ideal shape, they say. John Barten, water quality manager for Hennepin Parks (in Minnesota) and an advocate of P-free fertilizer, states, “… most lawns are not established on good soils. After the building is completed, the compacted ground is leveled with one or two inches of black dirt, and then seeded or sodded …. Unfortunately, neither grass roots nor rainfall can easily penetrate the compacted ground. As a result, the typical residential lawn cannot filter runoff like the test plots at research facilities.”
There is some truth to the claim that many lawns are established as Barten describes. But does that make it an argument against turf, or for properly established and maintained turf? After all, thick turf not only retains fertilizers that are applied to it, it also traps sediment, leaves and other sources of nutrients, making it a net benefit.
After hearing arguments on both sides, it's difficult to know what the evidence is trying to tell us. According to Barten, this is an argument against fertilizing turf with phosphorus. However, Barten's argument is based on the assumption that soil contains adequate phosphorus (which in some instances is correct). In that case, it's true that turf quality should not suffer without additional P inputs. On the other hand, turf growing in soil deficient in P would benefit from it, P being necessary to a healthy stand. The result should be thicker turf that reduces runoff.
The solution is to test soil and fertilize accordingly, in addition to performing other cultural practices necessary to a healthy turf. In fact, Barten strikes a similar chord, stating, “The good news is that we do not have to choose between poor lawns and clean lakes. By implementing [good cultural] practices, and raising the mower cut height to three inches or higher, the impact of lawns on water quality can be significantly reduced.”
Unlike P, nitrogen (N) is water-soluble in many of its forms. Thus, it potentially can enter groundwater via leaching and surface waters via runoff, even in situations where erosion may be minimal. However, even though N can leave the application site dissolved in water, rather than bound to sediment, the key is still slowing water down enough to allow it to infiltrate. This is because turfgrass roots are extremely efficient at absorbing N. Soil microbes also utilize N.
Investigators from major universities and the U. S. Golf Association (USGA) have studied this problem intensively. They found that very little N (less than 1 percent of the amount applied) leached if it was properly applied to well-maintained turf. This encouraging news even seems to hold true on sloped turf as well. In one study, researchers at Pennsylvania State University investigated N runoff on 9- to 13-percent slopes consisting of good-quality soil covered with creeping bentgrass and perennial rye. N was not found in runoff in significantly different quantities than in the water used for irrigation.
As you would expect, research has shown that certain factors can increase N losses. Heavier doses of N, especially soluble N, increase losses; sandy soils are more prone to leaching than clay (adding peat to sand, such as in greens mixes, reduces N leaching significantly); stressed turf is less efficient at trapping N than healthy turf; already-saturated soils are more prone to N losses than unsaturated soils; and compacted soils are more prone to runoff losses than permeable soils.
As with P, the moral of the story is that unhealthy, poorly maintained turf is susceptible to N losses, while thick, healthy turf is a N trap.
Compared to what?
Though some activists clearly would like to see it happen, eliminating turf altogether is not a good idea. Such an argument ignores a crucial issue: What would take its place? Pavement is one of the worst options because it traps no runoff. What about other types of vegetation? Better than pavement, perhaps, but healthy turf is known to have extremely dense root systems that hold the surface together as well as any type of planting. In fact, turf is arguably the best type of ground cover available if preventing soil erosion and runoff is your goal.
So let's back up a bit. If healthy turf is so beneficial, and the alternatives are limited, what's the problem? The problem (when there is one), may not be turf generally, but poorly maintained turf, much of it resulting from do-it-yourselfers. To give turf critics their due, many of the regulations they support aim squarely at what may be the most serious source of turf-related NPSP: homeowners.
Many homeowners possess several bad turf-care habits. For example, how many rely on Triple 12 or Triple 15 quick-release fertilizers for their landscapes, including turf? Quite a few. And how many over-throw fertilizer onto sidewalks, streets and driveways adjacent to turf? Many. Further, homeowners often neglect other cultural practices that would result in thick turf: aeration, regular overseeding, liming, etc.
That's why we'll see more regulations restricting P levels in fertilizer, even (or especially) for products sold in retail outlets. Don't expect exceptions to be made for turf professionals.
BMP — another acronym to remember
TMDL regulations compel states to identify best management practices (BMPs) to control non-point source pollution. State agencies and land-grant universities frequently are charged with developing BMPs. Many already have them and make them available online and in printed form. To turf professionals, BMPs usually look pretty familiar and often seem like nothing more than common-sense practices to limit fertilizer and chemical spills. However, some BMPs address, in detail, site, weather and cultural factors that affect pollutant mobility, as well as turfgrass selection, fertilizers, irrigation, mowing, pesticide use and other cultural practices. Existing BMPs mostly have been, until now, designed to be voluntary methods that homeowners and lawn-care operators can use to minimize nutrient loading. However, as TMDL regulations come into full force, BMPs in many locations will have the force of law.
Keep track of regulatory efforts related to TMDL that may impact turf care in your state. Talk to local government officials, extension agents and university experts. They can probably tell you if TMDL regulations will be affecting your area. It's crucial, if you want to influence regulations, to make your voice heard when it really counts — before the rules are finalized.
MANAGEMENT PRACTICES TO REDUCE NUTRIENT LOSSES FROM TURF
Best Management Practices (BMPs) developed by universities and state agencies may vary somewhat in their particulars and degree of specificity. However, the following are frequently cited as ways to reduce the risk of losing nutrients through surface runoff and leaching.
Water-in applied material, if appropriate, as soon as possible after application, but avoid applications if severe weather is impending.
Avoid spreading material onto paved areas. Use spreaders with side shields to keep fertilizers within the intended target area.
Use slow-release fertilizers.
Maintain thick, healthy turf with good cultural practices: proper mowing height, core cultivation, dethatching, good pest controls, etc.
Use fertilizer with appropriate N:P ratios (4:1 is common; many products go much higher). Avoid Triple 10 or similar “balanced” products.
Blow turf clippings back onto turf, rather than into the street.
Never allow fertilizer to be thrown directly into a body of water during application.
Use untreated and unfertilized buffer strips adjacent to bodies of water.
Educate your customers about proper watering practices.
Test your soils and adjust fertilization rates accordingly.
Avoid applying material that requires watering-in when soil already is saturated.
A TALE OF TWO FERTILIZER REGULATIONS
Of the many regulatory efforts aimed at fertilizers, we picked two that demonstrate how divergent such rules can be. As you'll see, some are more reasonable than others. The examples here were not designed to address TMDL requirements per se, but they are the kinds of regulations you can expect to see after TMDL rules take effect this October.
St. Johns County (Fla.) is our first example. For the protection of local wetlands experiencing rampant vegetation growth, in January 2000, the St. Johns Board of County Commissioners enacted a ban on quick-release fertilizers for lawn care. Specific exceptions were made for certain golf-course uses.
This regulation had several problems, according to local turf-care professionals. Among them were extreme enforcement measures that allowed county officials to stop and inspect any vehicle or equipment used for fertilizer application. Violators could face not only fines, but jail time as well.
The regulation allowed officials to conduct testing on the spot, which presented another problem. How do you test to see whether a fertilizer is water-soluble? You take a sample and grind it up. Since many slow-release products are simply granules of quick-release N with a coating around them, such testing would (accurately) show the presence of quick-release N even though the product was formulated as a coated slow-release material.
The St. Johns situation resulted in angry debate and legal wrangling (and still awaits final resolution). But it shows how local officials, unknowledgeable about fertilizers and, perhaps, unsympathetic to the turf-care industry, can impose well-meaning but poorly crafted laws.
Another problem came to light during the St. Johns episode. Because of the exemption for some golf course uses, finger pointing within the local turf industry began. LCOs felt unfairly singled out, while some local golf courses apparently were supportive of the regulations. Regardless of the particulars, it was instructive for the turf industry. It would be naïve to think that if one type of turf is targeted, others will not soon follow. Turf managers of all stripes need a unified voice.
A bill that was recently introduced in the Missouri House of Representatives exhibits more moderation than the St. Johns ordinance. Introduced this year by Rep. Judy Berkstresser, HB 914 is directed at phosphorus-containing fertilizers and is focused on specific counties around a single lake that some feel is suffering from excessive P levels.
The bill, if enacted, would limit the use of fertilizers containing more than 3 percent P on managed turf. Exceptions are made for soil that tests as deficient in P and for newly established (first year) turf. It also prohibits application of P-containing fertilizer to frozen or snow-covered ground, impervious services or on turf within 50 feet of a lake or stream.
The bill does not discriminate between homeowners and professional applicators and requires retailers to post and provide free literature to buyers containing consumer information and Best Management Practices developed by the University of Missouri Extension Service.
Perhaps the most burdensome requirement of the bill is that it requires commercial fertilizer applicators to be certified by the state. Unlike the drastic penalties included in the St. Johns ordinance, violators are subject to more reasonable punishments — $50 to $100 fines.
One might be inclined to argue with the need for the measure, or with some of its particulars, but at least it has been crafted reasonably enough that turf professionals will be able to continue to function if it becomes law.
Want to use this article? Click here for options!
© 2015 Penton Media Inc.