Durham housing developer allegedly violating Clean Water Act, jeopardizing Falls Lake

Falls Lake is going through some things.

Fertilizer is running off from farm fields, entering its tributaries. Toxic compounds known as PFAS, whose sources remain a mystery, have been detected at and near the dam. And when it rains, clay muck flows from large clear-cut lots, suffocating nearby streams that feed the lake.

Although the lake is the primary drinking water supply for a half-million people in Raleigh, Garner, Knightdale, Rolesville, Wake Forest, Wendell and Zebulon, land-clearing on the Durham County side of the watershed is a major contributor to the pollution. And one development in particular, Sweetbrier, a subdivision of 616 homes and townhouses being built by Clayton Properties/Mungo Homes, is central to a lawsuit filed in federal court last week.

Sound Rivers, a nonprofit environmental advocacy group, citing Durham County and state inspection records, as well as its own water quality sampling, alleged Clayton/Mungo has violated the Clean Water Act more than 20 times since last year. Clay and dirt, collectively known as sediment, has been documented leaving the 200-plus acre property and entering Martin Branch and Hurricane Creek, which flank the site. Both waterways feed Lick Creek, a direct tributary to Falls Lake.

Mungo Homes is a division of Clayton Properties, which is based in Maryville, Tennessee; the company operates in 18 states. Sound Rivers is represented by the Southern Environmental Law Center.

Mungo Homes officials did not respond to emails seeking comment.

Sedimentation in waterways is a serious problem. There are rules governing how much dirt can leave a development site and enter waterways, because bacteria can hitchhike on the sediment particles, entering the drinking water supply. The excess sediment can make it more difficult for utilities to treat and filter drinking water. And when too much dirt enters a waterway it can kill aquatic life, and ruin or impair its habitat. Similar incidents have occurred in Chatham County at the massive VinFast site.

Jonathan McNeil, Durham County erosion control supervisor, repeatedly warned Mungo it was out of compliance with its permit and asked that the company take “corrective action.”

Last February McNeil sent an email to Michael O’Sullivan, the company’s land development manager, alerting him to “repetitive substantial issues found on site ….” This included “open stream crossings with no ground cover, muck on slopes leading to the stream … I took 68 pictures of stuff that should not be happening…”

McNeil sent similar non-compliance notices in January 2023, as well as April, September and October 2022.

There are state standards for sediment in waterways, measured in “nephelometric turbidity units,” or NTUs. The higher the number, the cloudier the water, indicating a lot of dirt is present. For most rivers and streams that feed drinking water supplies, the state’s maximum level is 50 NTUs.

Since November 2022, “every time that Sound Rivers has conducted turbidity sampling at Martin Branch, it has documented exceedances of the North Carolina turbidity standard,” court filings read. Just two weeks ago, on Aug. 31, the turbidity level in Martin Branch was more than 1,100 NTU. Sound Rivers attributed this incident, and several others, to runoff from the Sweetbrier development. In addition, Sound Rivers documented exceedances of the state turbidity standard in Hurricane Creek four times in three months, also, the result of runoff from the site, according to court filings.

Sound Rivers is petitioning  the court to find that Clayton/Mungo is violating the Clean Water Act, and to penalize the company up to $64,618 per day, per violation, the legally allowable amount. In addition, Sound Rivers is asking the court to require the company to “immediately cease its ongoing and continuing” violations, and to remove from affected waters any sediment it is responsible for.