Summary of Delaware's Water Reuse Guideline or Regulation for Agriculture

This page is part of the EPA’s REUSExplorer tool, which summarizes the different state level regulations or guidelines for water reuse for a variety of sources and end-uses.
The source water for this summary is Treated Municipal Wastewater.

On this page:

• Technical basis
• Water reuse for agriculture approved for use in Delaware
• Water reuse treatment category for agriculture
• Additional context and definitions
• Water reuse for agriculture specifications (table)
• Upcoming state law or policy
• References
• Disclaimer

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This page is a summary of the state’s water reuse law or policy and is provided for informational purposes only. Please always refer to the state for the most accurate and updated information. 

In Delaware, water reuse for agriculture water reuse for agricultureThe use of recycled water for production of both crops for human consumption and non-food crops of commercial value. This reuse application excludes consumption by livestock, onsite non-potable reuse, and landscaping. includes spray irrigation onto unlimited and limited public access sites with agricultural land. The source of water (treated municipal wastewater) treated municipal wastewater Treated wastewater effluent discharged from a centralized wastewater treatment plant of any size. Other terms referring to this source of water include domestic wastewater, treated wastewater effluent, reclaimed water, and treated sewage. is specified by the state as domestic and municipal wastewater. The write-up uses state terms when discussing sources or uses of water that may differ from the Regulations and End-Use Specifications Explorer's (REUSExplorer's) terms.

Technical basis

Delaware approves the use of domestic and municipal wastewater for reuse applications related to spray irrigation on agricultural lands (7-60 Del. Admin. Code). All applicable provisions of the Clean Water Act (CWA) (33 U.S.C. §§ 1251 et seq.), including its implementing regulations, must be met in addition to any relevant rule requirements under the Food Safety Modernization Act (FSMA) (124 Stat. 3885). Reclaimed water used for agricultural irrigation is separated into two categories with different treatment requirements and performance standards based on site-access control (i.e., spray irrigation with unlimited and limited public access). Treatment requirements and performance standards are applied for the removal of microbial contaminants, chemicals and other relevant indicators related to agriculture and are summarized in the table. The technical basis for developing the specifications and/or removals of microbial contaminants, chemicals and other relevant indicators is not explicitly specified.

Water reuse for agriculture approved for use in Delaware

7-60 Del. Admin. Code defines the following approved water reuse for agriculture:

• Spray irrigation onto unlimited public access sites with agricultural land
• Spray irrigation onto limited public access sites with agricultural land

Delaware restricts certain uses of treated domestic wastewater for spray irrigation (7-60 Del. Admin. Code). These restrictions indicate that: 

• Crops irrigated with treated domestic wastewater must not be intended, utilized, sold or distributed for direct human consumption. 
• Forage crops must be harvested and removed from the irrigation field(s) at least twice a year. Crops harvested must be removed from the irrigation site within 6 months of harvest.
• Forage crops irrigated with treated domestic wastewater must be harvested before feeding to livestock.
• The grazing of animals on a site actively irrigated with treated domestic wastewater is prohibited.
• If domestic treated wastewater applications are terminated, the facility must adhere to the following precautions: 
  • Grazing by animals (other than lactating dairy cows) whose products are consumed by humans is prohibited for 1 month. 
  • Grazing by lactating dairy cows is prohibited for 1 year. 
  • Growing vegetables and root crops, which are eaten raw, is prohibited for 18 months. 
  • Hay must not be cut for 4 days after applications.
  • If the wastewater contains more than 25% industrial waste (excluding food processing industries) the forage must be monitored for potential toxicity problems to animals or possible food-chain effects. The monitoring requirements are designed on a site-specific, case-by-case basis. 

Water reuse treatment category for agriculture

In Delaware, all wastewater used for irrigation on unlimited access sites must be biologically treated, filtered and disinfected. State guidelines indicate that “This level of treatment is required to protect the health of persons who may come in contact with the irrigated wastewater” (7-60 Del. Admin. Code).

Wastewater effluent standards for domestic and municipal wastewater for BOD5, TSS and disinfection are based on site access control. In cases where public access cannot be restricted, levels of wastewater treatment need to be increased to assure comparable public health safeguards exist. 

Requirements include a comprehensive analysis to determine surface water impacts including the fate and transport of nitrogen and phosphorus and impact of with respect to dissolved oxygen, Enterococcus bacteria, total nitrogen and total phosphorus. This comprehensive analysis is part of the Surface Water Assessment Report that is submitted to demonstrate that nutrient performance standards for wastewater are being met at the post treatment location prior to reach the closest receiving surface water body.

Additional context and definitions

In Delaware, “agricultural land” is defined as land cultivated for the production of crops or used for raising livestock (7-60 Del. Admin. Code). "Crops for direct human consumption" means crops that are consumed by humans without processing to minimize pathogens before distribution to the consumer (7-60 Del. Admin. Code). "Spray irrigation" is defined as the controlled application of treated wastewater to a vegetated soil surface (7-60 Del. Admin. Code).

Water reuse for agriculture specifications

Summary of Delaware's Water Reuse for Agriculture Specifications

Source= 7-60 Del. Admin. Code

* Information about sampling and monitoring requirements such as frequency, site and quantification methods not specifically listed in the table was not explicitly specified in the State-specific regulations.

Upcoming state law or policy

No upcoming regulations pertaining to water reuse for agriculture were found for Delaware.

References

Clean Water Act, 33 U.S.C. §§ 1251 et seq.

Food Safety Modernization Act (FSMA), 124 Stat. 3885.

Large On-site Wastewater Treatment and Disposal System (LOWRDS) Performance Standards, 7 Del. Admin. Code § 7101-6.0.

Regulations Governing the Design, Installation and Operation of On-site Wastewater Treatment and Disposal Systems, 2014. 7-60 Del. Admin. Code.

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Disclaimers

Please contact us at [email protected] if the information on this page needs updating or if this state is updating or planning to update its laws and policies and we have not included that information on the news page.