MERCED - The deadline is fast approaching for farmers to sign up under the state's groundwater-quality management program, which requires growers to keep "nitrogen budgets."

Preliminary data suggest that hundreds, if not thousands, of commercial agricultural landowners have yet to sign up under the program.

Farmers in the Eastern San Joaquin River Watershed who are not registered by May 13 could face fines and penalties, according to officials with the Central Valley Regional Water Quality Control Board.

"We'd be looking at a formal order telling them they need to get regulatory coverage," said Joe Karkoski, chief of the Irrigated Lands Regulatory Program for the regional water board. "Then if they fail to do that, we could issue fines."

The program requires farmers to document the amount of nitrogen-based fertilizer applied to a particular crop. Farmers must factor in the nitrogen level of well water used for irrigation.

Nitrogen-based fertilizer, if overapplied, can seep into the groundwater and become nitrates. Nitrates have been linked to potentially fatal blue-baby syndrome, and are suspected of causing cancer.

This program sets a major precedent for regulating nitrates in groundwater, said Parry Klassen, executive director for the East San Joaquin Water Quality Coalition. "This is cutting-edge stuff, and how it works out is going to be unmatched anywhere in the country or the world."

The water-quality coalition has been chosen by the regional water board as a third-party agency to collect the nitrogen budgets from area farmers and submit regional data to regulators.

As of April, about 2,600 farmers had signed up with the coalition, representing 572,000 acres of farmland.

However, according to the water quality coalition, there are 150,000 to 175,000 unregistered agricultural acres in the five-county region, which comprises Merced, Stanislaus, Madera, Mariposa and Tuolumne counties.

Regional water board officials estimate there could be as many as 2,000 landowners that need to sign up.

"I wouldn't want anyone to get the impression that if there are a lot of them they will be able to avoid our scrutiny for very long," said Karkoski. "We haven't articulated publicly any enforcement strategies, but there are a variety of ways we could go forward."

Rather than registering with the water-quality coalition, farmers can sign up directly with the state. However, that process would be significantly more expensive.

If farmers choose to bypass the water-quality coalition, they will be charged an annual administrative fee of $750 for 10-to-100-acre farms, plus $5 an acre.

Membership dues for the water-quality coalition are $50 a member and $4 an acre.

Along with the nitrogen budgets, there are several reports that must be submitted to the water board, according to regional water board officials. The water-quality coalition will submit those reports for their members, but those signed up individually will have to submit their own technical reports. The reports, once submitted, are public documents.

"I have a pool of Ph.D. scientists writing these reports for the water board," Klassen said. "If you're doing it yourself, you have to hire those scientists to write the reports, and I guarantee it's not going to be cheap."

In an effort to get farmers signed up before the deadline, the water-quality coalition will hold several meetings.

The new-member meetings are scheduled for April 23 in Madera, and April 24 in Merced and Modesto. Meetings will be held at local farm bureau offices. Spanish and Hmong translators will attend each session.

Nitrogen budgets ultimately will be required of commercial farmers across the Central Valley, according to regional water board officials. The next area to be regulated will be the Southern San Joaquin Water Quality Coalition, which comprises Fresno, Kings, Tulare and Kern counties.