Manure Applicators Have Good Track Record
By Karen Grimes, Iowa Department of Natural Resources
Spreading manure is big business in Iowa. There were more than 400 commercial manure application businesses in Iowa and nearly 4,000 certified commercial and confinement site manure applicators as of Nov. 16, 2007. Together they spread roughly 50 million tons of manure annually, over two short periods of time each year.
These 1,612 commercial and 2,125 confinement site applicators have a good track record. Despite the long hours, they have been involved in a relatively small number of reported manure releases. As of Nov. 16, 2007, there were 58 for the calendar year, according to Iowa Department of Natural Resources’ records. Most of them happened at the facility, whether confinement buildings or open feedlots, see Table 1. (Note that confinements and open feedlots include facilities of all sizes.). Another way to look at that is averaged over all certified applicators, only 1.6 percent have had a reported manure release. Yet, as noted below, that percentage could be even less.
The number one cause of manure releases in 2007 was human error. (See Table 2.) The specific examples vary from leaving a pump while it’s running to tipping over a spreader to forgetting to shut a valve completely. These were preventable events.
Other causes include a number of equipment failures: blocked pipes, hose leakage and pumping failure. Even the category “applicator failure” is due to a failure of application equipment. Added together they are significant sources of manure releases. For applicators and for livestock producers, the message seems clear. It’s important to maintain and check equipment frequently.
Although training for certified applicators plays a part in preventing manure releases, the one factor that seems to play a large role is the weather. Wet, rainy falls produce more manure spills than long, dry falls. However, DNR field inspectors indicate that because of the training, certified applicators are better prepared to prevent releases from reaching a water of the state. They know what to do and where to go for resources.
Other common causes of manure releases include rainfall, saturated fields that readily run off, accidents and overflows from pits or basins.
The fall of 2007 was particularly challenging because of heavy rainfall in parts of the state. Fields were too wet to harvest or too wet to apply manure. Producers had to deal with manure storage structures that were close to overflowing. Still, when the structure fills up, producers should call the DNR field office to discuss alternatives to an overflow.
Not all releases are reported, but all releases are required to be reported to the DNR, regardless of the type or size of livestock operation or the size of the release. In some cases, releases that first appeared to be minor were observed and reported by a neighbor or caused a fish kill. In many cases, DNR specialists have experienced a similar situation and can offer ideas or suggest resources to minimize damage to the environment. Producers and applicators should remember they are required by Iowa law to call the 24-hour spill line, (515) 281-8694, within six hours of the onset or discovery of the spill. The sooner you call, the more likely downstream water quality problems can be avoided or reduced.
Location of Manure Spills
As expected, the location of manure releases parallels the location of the majority of manure applicators and the concentration of livestock and poultry operations. Map 1 shows the number of reported releases by Iowa county.
However, location does not seem to be a factor for the amount of manure released. (See Map 2) Reported releases ranged from 5 to 40,000 gallons. Four releases in 2007 were for amounts of 10,000 gallons or more. The causes included: a broken manure transfer pipe, a plug lost when draining nursery building flush pits and a possible plumbing problem (all 10,000 gallons).
The fourth was a release of 40,000 gallons which occurred when an automatic high pressure line broke. The line was used to wash hog buildings with effluent from a lagoon.
1. Source of information – IMMAG FAQs. Includes liquid and dry manure.