Lubbock is attempting to deal with a problem of noncompliance with nitrate levels in treated wastewater by getting rid of thousands of prairie dogs who live in the field where the wastewater is sprayed.
The causes reach back over decades. For more than 70 years Lubbock has been spraying "gray" water (wastewater that has been through primary treatment) on 6,000 acres east of the city. The wastewater, rich in nitrates, has produced bumper crops of corn, cotton and, most recently, rye grass, now being grazed by a herd of heifers and a growing colony of prairie dogs.
Over the years those nitrates also have accumulated in the soil and percolated down to the Ogallala Aquifer, adding to the pollution that already exists in West Texas' primary water source. That pollution accumulated to the point that in 1989 the TNRCC ordered the city to improve the groundwater quality below the fields.
The fields are watered by a process called "center point irrigation," in which massive, wheeled sprayers move around a circle from the middle of the field, leaving only the corners untouched by their spray. Those corners have always been home to a few prairie dogs, said site manager John Hindman, but in recent years their numbers have grown.
"We used to rotate the crops and we plowed every year," said Hindman. "Then, around 1992, we planted rye grass."
Rye grass, an Italian import, is said to absorb large amounts of nitrates. Its dark green stems now cover about 3,000 of the city's 6,000 sewage treatment acres. It is a protein-rich fodder for cattle, but prairie dogs thrive on it as well.
"I don't know why, but about four years ago the prairie dogs started to increase," said Hindman. "Now they're taking over. They're completely covering the corners and working their way out into the middle."
No one knows how many prairie dogs occupy the site, but Texas Parks and Wildlife has estimated 40,000 to 50,000. Nor does anyone know exactly how many holes they've dug.
It was the holes, however, that drew the attention of the TNRCC. On June 3 Pat Cooke, a TNRCC field investigator, found that nitrate contents in monitoring wells at the site had spiked. He issued a now infamous noncompliance notice to the city, directing it to come up with a plan to lower the pollution by Aug. 6.
In it, he cited prairie dogs and made the somewhat broad speculation that: "explosive growth of the prairie dog population could lead to crop failure due to overgrazing, which, in turn, could allow effluent constituents to migrate further into the soil and possibly the groundwater."
He then directed the city to come up with a plan to control the prairie dog population.
The usual suspects are up in arms, with some of them noting that it's nothing but one man's say-so that the prairie dogs are the cause of the problem. There is, of course, the question of what to do with several thousand displaced prairie dogs. Linda Watson, who has been busy trapping them since the noncompliance memo was released, relocates some of them, including across the ocean:
"There're not that many places you can put them, of course," said Watson. "Parks and Wildlife has been taking some to a state park near San Angelo. There are some philanthropists and, then, there are the Japanese."
Prairie dogs have become a popular pet in Japan in recent years and Watson has built a following there.
"They're great pets for the Japanese," said Watson. "They're absolutely nonagressive. They only bite in the wild and then only when you grab them. They're smart, they're born housebroken and they don't take much room. I hear the Japanese are even registering them now."
Larry, naturally, also noticed this.Posted by Charles Kuffner on August 05, 2002 to The great state of Texas