September 23, 2018. A serious storm accompanied by flooding has many environmental impacts and most are all too familiar to North Carolina from past storms. Once the immediate rescue phase has ended, the Department of Environmental Quality (DEQ) has a larger role in hurricane response than the public may realize. Some of the environmental challenges:
♦ Disabled water treatment and wastewater treatment systems. Large storms can disable environmental infrastructure like water and sewer systems because of lost power, inundation by flood waters or runoff overwhelming the sewage collection system. Any of those impacts can result in release of contaminants, including untreated sewage.
♦ Disposal of storm debris. Wind damage and flooding creates a huge volume of storm debris: downed trees; construction debris; drywall and flooring removed from flooded homes; sodden carpet; ruined furniture and appliances; animal carcasses; and hazardous materials like paint, solvents, pesticides and other chemicals. Debris from older structures may contain asbestos. DEQ’s Division of Waste Management (DWM) works with local governments to pre-approve new landfills for vegetative waste and non-hazardous construction debris before a storm hits. But hazardous materials damaged or uncovered by the storm can complicate and slow debris removal because those materials need to be separated for disposal. Improper disposal of hazardous materials can cause groundwater or surface water contamination; burning hazardous materials with other debris may expose nearby residents to dangerous air quality conditions and create a risk of explosion. Failing to separate and properly dispose of hazardous materials also has a cost; the Federal Emergency Management Agency (FEMA) will not reimburse the state for debris collection and disposal that violates federal hazardous waste laws. Unfortunately, storms never sort debris and efforts to clean out flooded homes often create piles of trash that include both hazardous and non-hazardous materials.
♦ Release of contaminants from landfills and dumps (legal and illegal) inundated by floodwaters; spills from above-ground and underground petroleum storage tanks; and releases from other types of chemical storage facilities. The U.S. Environmental Protection Agency (EPA) emergency response program works with the state DWM and Division of Water Resources (DWR) to respond to these environmental incidents.
♦ Clearing debris from rivers, streams and drainage ditches. Large storms also deposit downed trees, limbs, and other debris into streams, rivers and drainage ditches obstructing flows. Removal of debris from streams and rivers may require a federal permit under Section 404 of the Clean Water Act. (Any method of removal that would disturb the stream bottom or riverbed requires a permit.) The U.S. Army Corps of Engineers issues the Section 404 permits, but state water quality and coastal management staff also have a role and frequently help determine whether the permitting requirements apply to a particular stream or drainage feature. DEQ provides a guidance document on stream clearing to help citizens understand how to do the work without violating federal rules.
♦ Animal waste. Updated information on swine waste lagoons (as of noon on September 22, 2018):
Animal Operations – Swine Lagoons
Category | Total # Facilities/Lagoons |
Structural Damage | 5 facilities/5 lagoons |
Discharges (Overtopping) | 28 facilities/34 lagoons |
Inundation, no indicated discharges | 7 facilities/9 lagoons |
Freeboard 0″ | 10 facilities/12 lagoons |
Freeboard 0-3″ | 25 facilities/35 lagoons |
The table above comes from DEQ’s Dashboard. The first category, waste lagoons with structural damage, need repair to stop the release of swine waste through the damaged lagoon wall. Lagoons that are overtopping (the second category) have been inundated by flood waters and are spilling wastewater mixed with floodwater over the top of the lagoon wall. The other three categories describe swine waste lagoons that are full or nearly full, but not actively releasing wastewater to the environment.
All of these lagoons (and an unknown number of additional lagoons with only slightly more storage capacity) may continue to be a concern for weeks or months beyond the storm. The problem is this: the entire swine waste management system depends on the ability to regularly spray wastewater from the lagoon onto a crop as fertilizer. Spraying down the lagoon level makes room for storage of new waste coming from the hog houses. State permits for lagoon and sprayfield systems limit spraying to the amount the receiving crop can use as a nutrient (to avoid contaminating groundwater with excess nitrogen or phosphorus) and prohibit spraying swine waste on already-saturated ground to avoid runoff. Under those permit conditions, spraying down lagoon levels may not be possible for some period time after the storm has ended because surrounding agricultural lands remain saturated. In the past, the tension between a need to lower lagoon levels to prevent additional breaches and the environmental impact of spraying wastewater on saturated soil has led to some difficult and controversial policy decisions. Farms have also sometimes needed to remove animals for a period of time because of the lack of waste storage capacity.
Although poultry operations get less media attention than the swine farms, flooding also sweeps poultry waste into floodwaters and creates similar problems for post-storm land application of poultry waste onto agricultural fields.
Coal ash releases. Historically, much of the coal ash produced by coal-burning power plants in N.C. has been disposed of in open ponds that work on the same principle as the swine waste lagoons – solids go to the bottom of the pond and water levels are lowed periodically by pumping from the top layer of water. The difference is that Duke Energy has Clean Water Act permits allowing discharge of water from the top of the coal ash ponds into a nearby river, lake or stream. Permit conditions limit the volume to levels that will not cause a violation of water quality standards in the water body receiving the discharge. Hurricane Florence has already caused a significant breach in the dam separating Sutton Lake from the Cape Fear River. The lake receives a wastewater discharge from the Sutton plant’s coal ash pond. DEQ has also documented erosion/wash-out of coal ash from older, now vegetated coal ash basins at the Lee Plant (Goldsboro). DEQ has posted video of the Sutton site and photographs of washover from the Lee ash basin on the Dashboard coal ash page.
Going forward, the question will be what kind of repair/restoration/remediation may be required to address the coal ash releases.
Disposal of dead animals. Disposal of a large number of animal carcasses following a storm has environmental implications, but falls under the responsibility of the State Veterinarian in the Department of Agriculture and Consumer Services. To date, the Agriculture department has reported over 3 million poultry and more than 5,000 swine killed by Florence and those numbers may rise. Under state law (G.S. 106-403), dead animals can be buried under three feet of soil or disposed of in any other way approved by the State Veterinarian. Some of the alternative disposal methods used in the past include composting (particularly of poultry); rendering for use in animal feed; and incineration. In the past, burial has raised concern about potential for groundwater contamination since many of the large animal operations affected by flooding are located in southeastern counties with naturally high water tables. Although G.S. 106-403 requires a burial site to be at least 300 feet from a “flowing stream or other public body of water”, the law doesn’t expressly take groundwater impacts into consideration.
Dam failures and landslides. DEQ’s Division of Energy, Mineral and Land Resources responds to dam safety emergencies and oversees repair/reconstruction work under the state’s Dam Safety Act. The same division has a role in responding to landslides. Heavy rains associated with Florence caused several landslides in mountain counties that closed roads, but thankfully did not cause any deaths.
Rebuilding. Looking beyond storm response and cleanup, rebuilding in coastal areas becomes a significant permitting challenge for state water quality and coastal management agencies. Once floodwaters recede, staff in the state Division of Coastal Management (DCM) helps FEMA do initial damage assessments to distinguish repairable buildings from those that have more than 50% structural damage and require reconstruction. Some number of the heavily damaged/destroyed structures will raise policy issues about whether or how to allow rebuilding. Older, “nonconforming” structures that did not meet current building code, zoning or coastal development rules before the storm may not be able to meet those standards to rebuild. Some of the most difficult post-storm reconstruction decisions involve buildings that cannot meet current stream buffer or oceanfront setback requirements.
DCM uses special emergency permits developed in response to past storms to allow routine reconstruction to begin quickly. The emergency permits cover reconstruction of buildings and accessory structures (such as docks) that can be rebuilt in their previous location and within the same footprint.
Update note: The original blogpost has been revised to clarify that the dam between Sutton Lake and the Cape Fear River breached rather than the coal ash pond.