COURTLAND—Hercules Inc. would pay a $12,800 fine for discharging dangerous chemicals into the Nottoway River this summer under a proposed agreement between the company and the state.

The July incident resulted in temporary restrictions being placed on fishing, swimming, wading and consuming fish caught in the river. It also caused the death of hundreds of fish and reptiles in and around a discharge canal between the chemical plant off of Route 671 and the Nottoway.

A consent special order drafted by the Virginia Department of Environmental Quality calls on the company to pay the fine, as well as a $162.18 reimbursement for the cost of investigating the fish kill.

It also would require company officials to identify the root cause of the incident, describe ways they intend to keep such an incident from occurring again and evaluate ways the plant can limit its use of groundwater.

Company officials said Friday they consider the agreement to be fair, and they already have made changes designed to keep a similar event from happening in the future.

Paul Smith, a DEQ enforcement specialist, praised Hercules’ response to the chemical release.

“They’ve done a good job,” he said. “They took immediate action to clean up the spill as quick as they could, and they have taken steps to avoid another in the future.”

He said he is satisfied with the steps the company has taken to ensure another such release will not happen.

Two major changes the company has made address the external heat exchanger that was the source of the problem in July, when about 640 gallons of tert-butyl hydroperoxide (TBHP) and 1,200 gallons of dimethylbenzyl alcohol (DMBA) drained from a damaged heat exchanger into cooling water and thence into the river.

The chemicals are used in a monthly process Hercules completes for GEO Specialty Chemicals in the production of a compound used to make certain rubber products stronger and more durable.

The company’s analysis of the incident showed that the heat exchanger had been severely damaged by decomposition of residual chemicals that had not been flushed from the system when the operation previously ran in June.

When the chemical mixture circulated through the heat exchanger, the equipment was unable to contain it, and the chemicals were discharged into the equipment’s cooling water, which eventually drains into the Nottoway.

Since discovering the root cause of the incident, the company has begun diverting water from the heat exchanger to a containment area to protect the river in case of another chemical spill, according to Roy Hart, Hercules’ safety, health and environmental manager.

Operating procedures also have been changed to require the heat exchanger to be drained after each month’s operation and to require employees to verify it is intact before using it each month, he said.

The company is also studying whether it can install instruments to test for small amounts of chemicals in the cooling water it uses.

“If it happened once, it can happen again,” Plant Manager Andrew B. Chapman said Friday. “So we have to put operations in place” to keep chemicals out of the environment.

“We have changed our procedures,” he added. “We have taken the human factor out. We take our responsibility seriously.”

The proposed agreement between Hercules and the DEQ is subject to a 30-day public comment period, at the end of which the State Water Control Board will review it and decide whether to approve it. The board’s next meeting is Dec. 4 in Richmond.

Following the board’s approval, the company has 90 days to complete the agreed-upon actions.

Hercules officials already have taken steps locally to rebuild the company’s environmental credentials. In September, Chapman said, he and Hart met with members of the Blackwater Nottoway Riverkeeper Program and explained what happened to cause the chemical release, as well as their plans to avoid another.

Chapman said he could understand the frustration apparent in comments made at the time by Riverkeeper Jeff Turner, who pointed to the company’s record of chemical spills and said, “I’m about tired of this.”

“They’re valid comments,” the plant manager responded on Friday. “We have not had the record we should have had.”

“He sounded pretty sincere to me,” Turner said Friday of Chapman’s visit to the Riverkeeper group. “He sounded like he was pretty upset himself about what is going on.”