DNREC renews Clean Delaware’s land application permit

The state has reauthorized the agricultural utilization permit allowing for Milton-based Clean Delaware to continue the land application of biosolids, septage and other approved wastes at the company’s locations in Milton and Harbeson.

Delaware Department of Natural Resources and Environmental Control Secretary Shawn Garvin issued an order Jan. 3 renewing the permit.

“I find and conclude that the applicant has adequately demonstrated compliance with all requirements of the applicable statutes and regulations ... and is continuing to work with the department to assure that all commitments and compliance requirements are met,” said Garvin.

Clean Delaware’s existing permit authorizes the land application of biosolids generated at small-volume wastewater treatment facilities that have undergone a process to significantly reduce pathogens onto three non-contiguous sites comprising a total of approximately 228 acres of land suitable for crop production.

The sites include one about one mile northwest of Milton, one about two miles east of Ellendale and one in the center of Harbeson. As part of the permit renewal, and at the request of Clean Delaware, the Ellendale site has been removed from the permit as a place that can be used for land application. The existing permit also authorizes the application of lime-stabilized septage that has undergone the process to reduce pathogens onto designated portions of the Milton site.

Clean Delaware General Manager Gerry Desmond said the company hasn’t land applied to the Ellendale field in almost a decade because it was cost prohibitive due to the field being sandy. It’s never been a high-producing field, so the company decided not to renew the lease it had with the farmer who owned the land, he said.

Clean Delaware’s Milton site is about 170 acres, split among seven fields, and is the location of the company’s processing center for septage and equipment. The Harbeson site, located immediately southeast of the intersection of Routes 5 and 9, is about 24 acres. 

According to the secretary’s order, septage is defined as sewage pumped from a septic tank that has been treated to significantly reduce pathogens, not raw sewage from a septic system. Additionally, the order reads, biosolids are also not raw sewage; instead, they are one of the final products from the treatment of municipal wastewater at a wastewater treatment plant that has undergone an approved pathogen-reduction process.

Clean Delaware must meet a number of requirements as part of permit approval – sampling of biosolids to test levels of nutrients, metals, percent solids, pH levels, etc.; retaining a 20-inch separation from the depth of tillage to the seasonal high groundwater table; groundwater monitoring; application of materials at a rate to ensure applied nutrients do not exceed the crop requirement; maintenance of buffer zones from wells, streams, ditches, property lines, houses, etc.; limitations to land application so that it does not occur during adverse weather conditions, such as rain and snow; harvest restrictions dictating the length of time before crops can be utilized; public access restrictions for sites that receive biosolids; planting of cover crops required in the winter after application occurs during any given year.

Additionally, the order says, DNREC routinely inspects approved biosolids land application sites, both during and after application activities, to ensure compliance with permit conditions.

According to the order, an anemometer and windsock are installed at the Milton site and septage shall not be applied when sustained winds exceed 10 mph or wind gusts exceed 15 mph. Additionally, Clean Delaware will ensure that any aerosols created by land application do not carry beyond the property boundaries.

The current sampling requirement for metals is every three years. However, the proposed frequency is once every five years (once per permit cycle). The annual sampling of biosolids will remain unchanged.

Historically, says the order, metals have been well below risk-based standards in the land-applied materials. Soil data spans over 30 years and demonstrates metals in soil continue to be well below standards and are not accumulating in the soil, said the order.

As part of permit renewal, the state sees no need to continue measuring the groundwater levels in the active land application field.

According to the order approving the permit, Clean Delaware’s land application sites greatly exceed the 20 inches of separation required from the depth of tillage to the seasonal high groundwater level. Historically, said the order, Clean Delaware’s minimum separation has been 7 feet. However, groundwater levels will still be monitored as part of the routine quarterly monitoring that occurs at all of the company’s application sites.

Under the renewed permit, the state will require that the timing, quantity and quality of sludge to be land applied is determined by a Delaware-certified nutrient management consultant and specified in the site-specific nutrient management plan.

Midway Services transporter permit amended

In addition to renewing Clean Delaware’s agricultural utilization permit, Garvin issued an order amending an existing nonhazardous liquid waste transporters permit that allows for Midway Services, based in Lincoln, to transport septage to Clean Delaware for final disposal.

This is the third time Midway’s transporters permit has been amended since 2019.

In February 2019, the state issued a permit allowing Midway to dispose of its nonhazardous liquid waste – septage, holding tank waste, grease trap and/or cooking oil waste – to the Kent County sewer system at locations in Smyrna or Milford. The permit was amended again in April 2019, this time allowing Midway to dispose of its waste into the Sussex County sewer system at the county’s Inland Bays treatment facility outside Millsboro.

Midway’s existing transporters permit is currently in effect until Feb. 8, 2024. According to Garvin’s order, the septage transported by Midway will be lime treated and land applied in accordance with Clean Delaware’s agricultural utilization permit issued by DNREC.

“In reviewing the applicable statutes and regulations, as well as weighing public benefits of this project against potential detriments, the department’s experts in the Division of Water have concluded that the pending application complies with all applicable federal and state laws and regulations,” said Garvin in his order Jan. 3.

Even with the amendment, Midway’s transporters permit still allows it to utilize Kent and Sussex infrastructure and facilities for the disposal of septage and other waste streams.