Paper mill logs new violation: Investigation continues into black liquor seep
The now-shuttered paper mill in Canton has received a new violation for exceeding permit limits on toxicity for water released from the plant, continuing a pattern established over the last two years of averaging more than one notice of violation every two months.
In nearly identical language to a separate notice of violation issued Aug. 2, a Sept. 19 letter from the N.C. Department of Environmental Quality notifies Pactiv-Evergreen that the toxicity levels it measured in June violate the limits in its wastewater discharge permit.
June 2023 was a pivotal month for the mill and for the region surrounding it. Workers left their last shift at the 115-year-old plant on June 8. The mill now sits idle save for its wastewater treatment plant, which under an agreement dating back to the 1960s must continue to treat the Town of Canton’s waste for two years after the closure . The wastewater treatment plant also treats leachate from the mill’s landfill and stormwater flows on the mill site.
The mill’s wastewater discharge permit requires it to perform quarterly tests to ensure that discharge from the plant doesn’t have “observable inhibition of reproduction or significant mortality to Ceriodaphnia dubia at an effluent concentration of 90%.” Commonly known as the water flea, C. dubia is a tiny aquatic invertebrate that is used as an indicator to measure water toxicity. If the species can’t survive, the water quality is likely poor.
A test performed in June showed marked mortality at a concentration of only 45%, well below the 90% concentration for survival stipulated in the permit. Water fleas in the control group produced an average of 29.2 young, with that number dropping to 8.8 young at a 45% concentration. At a 75% concentration, the average was only 1.1, and it was 0 at 90%.
This marks the second quarterly test in a row that the mill has failed. March testing also showed a substantial impact to water flea survival at a concentration below 45%, but June test results indicate an even greater effect. In March, the control group averaged 30.9 young, with an average of 22.2 at a 45% concentration — more than double the 8.8 average observed in June. In results from tests performed 2019-2023, water fleas were able to reproduce uninhibited even at an effluent concentration of 100%. In addition to the failed tests in March and June 2023, the only exception was June 2022, when the result was 97.5%.
The Sept. 19 letter directs the mill, which ceased production in May, to “take whatever remedial actions are necessary to eliminate the conditions causing the effluent toxicity violation(s).” These efforts could include conducting a toxicity reduction evaluation, a site-specific study to identify what caused the toxicity, isolating the sources of the toxicity, evaluating the effectiveness of toxicity control options and confirming reductions in effluent toxicity.
This new violation brings the mill’s total since May 2021 up to 16, including six in 2023. According to a DEQ spokesperson, the mill passed required follow-up tests for both the March and June toxicity tests, and no further enforcement action, such as fines, will be taken. The mill was not required to file response letters to these violations. Enforcement actions for a July 10 violation, in which DEQ accused Pactiv Evergreen of illegally dumping chemicals into its wastewater system during the shutdown, are under review. In a response letter , the company contested the allegations, saying it had acted “on a good faith belief” that the discharge was legal.
DEQ continues to work with the U.S. Environmental Protection Agency on assessment and remediation for black liquor flows that have periodically been observed seeping into the Pigeon River. Black liquor is a caustic byproduct of papermaking that is extremely toxic to both humans and aquatic life. Pactiv Evergreen’s environmental staff found the substance “visibly present” in the river on Jan. 28, 2022, and it was determined to be related to an ongoing issue that received its first notice of violation in 1994.
According to an April 22, 2022, letter from Collin Day, regional supervisor for the DEQ’s Inactive Hazardous Sites Branch, the discharge into the river is likely associated with this documented groundwater contamination. Also in 2022, Pactiv Evergreen received separate notices of violation from the DEQ’s Division of Water Resources and Division of Waste Management related to he seep.
In September, a comprehensive groundwater and surface water assessment was conducted to shed light on the black liquor issue. Samples were collected at 29 groundwater monitoring wells and four surface water sites along the Pigeon River and will be analyzed for 160 organic and inorganic constituents. Additionally, DWR has been conducting weekly monitoring on the Pigeon River upstream and downstream of the mill since May.