Environment

U.S. embarks on a national air emissions study

Under pressure to regulate livestock operations through federal air quality laws, the federal Environmental Protection Agency is gathering scientific data to determine which producers meet the standards

by SAM BRADSHAW

One year ago, the Canadian Pork Council (CPC) initiated a meeting with the U.S. National Pork Board’s Environment Committee. It was a good experience, so this year we went to Des Moines, Iowa, to meet with them again and share information on environmental issues.

I attended all of the sessions, along with Danita Rodibaugh, president of the National Pork Board attended all of the sessions along with Canadian Pork Council chair Clair Schlegel and Bill Wymenga, chair of Ontario Pork’s Environmental Committee.

It came as no surprise that the issues U.S. producers face are not much different than those we are looking at in Canada. Water and air quality standards seem to be in the forefront.

So what are some of the major U.S. concerns?

• Swine worker health issues are getting much more attention, especially air quality inside barns, as workers are spending much more time in the barn these days – in many cases, eight hours or more. There is also a push to provide quieter barns, both for swine workers and for the animals. Some researchers in Ontario believe that noisy barns can have an effect on breeding productivity.
  
  
• Much effort is being spent to quantify the risks of pathogens, antibiotics or other possible contaminants. Our U.S. counterparts are also trying to identify workable interventions for identified risks.
  
  
• U.S. researchers are trying to trace contaminants using antibiotic resistance source tracking, a method we in Ontario have determined not to be very effective.
  
  
• The major effort seems to be aimed at studying the effects of possible airborne contaminants downwind of barns, including odour.

The United States is embarking on a national air emissions study and trying to gather valid scientific numbers to use to regulate the livestock industry. Historically, in the United States, federal air quality laws were written and enforced against smokestack industries. In recent years, the federal Environmental Protection Agency (EPA) has been under pressure to regulate livestock operations through federal air quality laws.

In 2003, the National Academy of Sciences released a report calling for the EPA to improve its methods for estimating livestock operation emissions. The purpose of the study accompanying the agreement is to provide the EPA with better data to determine which livestock operations meet or exceed the thresholds in the federal air quality laws.

Recently, the EPA offered livestock farmers the chance to participate in a voluntary “Air Emissions Consent Agreement.” Farmers who sign the agreement will be given some protection from enforcement for prior violations of three federal air quality laws.

The offer was open until Aug. 12, 2005, to swine, dairy and poultry producers who raise animals inside barns and to persons who contract with producers to raise animals.

The main pollutants in question are hydrogen sulfide, ammonia, volatile organic compounds and particulate matter. After Aug. 12, 2005, 16 static monitoring sites will be selected from among the agreement participants.

Producers who enter the agreement receive safe harbour for emission violations during the past five years. This prevents any EPA enforcement action until the study is completed. The monitoring will be completed by 2008 and the decision on standards will be completed by 2010.

Iowa State University is also researching air quality and has a rather amazing air quality laboratory. Staff have suggested that standards for hydrogen sulfide (H2S) could settle out at about 30 parts per billion (ppb) for no more than seven one-hour durations per year, measured at the minimum distance separation location. This minimum separation is the distance a new barn would have to be from a neighbour’s house or other non-agricultural use.

Ammonia is being monitored but, so far, no standards have been proposed. Odour monitoring is complete but no standards have yet been established for it either.

Concentration and duration must be considered when determining allowable emissions. Duration schedules fall under the following time frames: acute, one to 14 days; intermediate, 15-364 days; and chronic, more than 364 days.

Iowa State University researchers are monitoring particulates at a residence 2,200 feet from: 2,000-4,000 head deep pit hog barns. They are finding, for example, that ammonia levels of one ppb outside the residence go up to seven ppb sporadically at this separation distance.

Some feel that the government will try to set agricultural ammonia levels of 100 ppb at the separation distance. It is interesting to note that the university measured 100 ppb ammonia inside the house after a technician had smoked two cigarettes. Some researchers believe that ammonia is added to cigarettes to increase the uptake of nicotine.

The researchers also measured 1,800 ppb after the technician cleaned the floor using an ammonia-based cleaner. A scientist told us that the concentration of ammonia must be about 2,000 ppb before one can smell it.

University of Iowa civil engineering professor William Eichinger has received a three-year, $406,000 grant from the U.S. Department of Agriculture to develop a new approach for minimizing the release of emissions from livestock facilities.

The project is designed to determine how chemicals emissions are released from livestock facilities and propose ways to solve the problem. This laser is a $750,000 piece of equipment that will shoot a beam up to three kilometers and detect particulate matter, while at the same vaporizing anything in its path (which makes it necessary to obtain authorization before each use). "Lidar (laser radar) devices are capable of mapping the concentrations of particulates and some chemicals in the atmosphere," says Eichinger. Mapping can be fast enough to make “movies” of emissions from barns.

These movies have shown that the way effluents are released is quite different from conventional assumptions. Early findings suggest that air doesn’t move away from barns in a neat elongated plume or bubble, as was previously thought, but moves away sporadically in pieces or chunks. It also emerged that wind blowing at right angles to a normal pitch roof on a barn will cause the air to move up to several times the height of the barn, taking gasses and odour with it.

Iowa State University also has an Air Management Practices Assessment Tool, whose purpose is to guide producers through a process of determining which mitigation practices are best suited to their operation and objectives. The Web site is organized into four air emissions of interest - dust (particulates), odour, ammonia and hydrogen sulfide. Within each gas or emittant, sources of emission are categorized by housing, manure storage, or land application.

To access this site go to http://www.extension.iastate.edu/airquality/practices/homepage BP

Sam Bradshaw is environmental specialist with Ontario Pork.BP