Summary of Illinois’ Water Reuse Guideline or Regulation for Landscaping and Onsite Non-potable Water Reuse
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 Rainwater Collected Onsite.
- Technical basis
- Onsite non-potable reuse approved for use in Illinois
- Water reuse category/type
- Additional context and definitions
- Onsite non-potable reuse specifications (table)
- Upcoming state law or policy
- References
- Disclaimer
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 Illinois, water reuse for landscapingThe use of recycled water on land to assist in the irrigation of vegetation in residential and non-residential areas. Includes impoundments to store water for irrigation , ornamental vegetation, parks, school yards, sporting facilities (including golf courses), private gardens, roadsides and greenbelts, and cemeteries. Excludes irrigation of areas used for agriculture, commercial reuse applications, or any centralized non-potable reuse. reuse applications include lawn sprinkler systems, subsurface irrigation and surface irrigation. onsite non-potable water reuse The use of treated onsite collected waters for non-potable purposes at the single-building or district scale. This reuse application excludes the use of recycled water from a centralized treatment and distribution system for landscape irrigation or commercial uses. applications include water closets, urinals, fire safety systems, clothes washing, HVAC cooling water, decorative fountains, vehicle washing and ice rinks. The source of water rainwater collected onsite Precipitation collected at the district or regional scale is classified separately under 'stormwater.' is specified by the state as rainwater. 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
Illinois approves the use of harvested rainwater for onsite non-potable water reuse applications, including for fire safety systems, water closets and urinals and lawn sprinkler systems (SB0038 2012). Illinois requires rainwater harvesting collection and distribution systems to be used only for non-potable uses and systems to be constructed in accordance with the Illinois Plumbing Code (IPC) by an Illinois licensed plumber based on the end use application (SB0038 2012). 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 state water quality standards. Plans and specifications for a rainwater harvesting system must be submitted for approval before installation when the rainwater system collection and storage is greater than 5,000 gallons, end use applications are not considered under CSA B805-17/ICC 805 2018 or populations potentially impacted by the end use of onsite water are considered at risk (Illinois Register, 2018). Illinois cites the CSA B805/ICC 805 (2018) as the source of treatment requirements or performance standards for the removal of microbial contaminants, chemicals or other relevant indicators related to onsite non-potable water reuse. The technical basis for developing the specifications and/or removal of microbial contaminants, chemicals and other relevant indicators for harvested rainwater used for non-potable reuse application is not explicitly specified.
Onsite non-potable water reuse applications approved for use in Illinois
The Illinois Register (2018) defines the following specific onsite non-potable water reuse applications for treated rainwater from non-potable rainwater collection and distribution systems:
- Fire safety system
- Water closets
- Urinals
- Lawn sprinkler systems with sprinkler heads at single family, multi-family and non-residential dwellings
The Illinois Register (2018) directs to CSA B805/ICC 805 (2018) for further rainwater harvesting specifications. CSA B805/ICC 805 (2018) provides examples of additional onsite non-potable water reuse applications such as:
- Surface and subsurface irrigation (drip, bubbler)
- Clothes washing
- HVAC evaporative cooling
- Decorative fountains
- Ice rinks
- Vehicle washing
Additional onsite non-potable water reuse applications for treated rainwater from rainwater collection and distribution systems are not specified by Illinois.
Water reuse treatment category/type
The collected rainwater must meet the minimum roof runoff water quality requirements for each end use application provided in CSA B805/ICC 805 (2018). CSA B805/ICC 805 (2018) assigns reuse applications to end use tiers, which have a corresponding potential for human contact.
- End use tier 1; Low potential for human contact
- For both single-family residential applications and multi-residential and non-residential applications: There are no minimum requirements.
- End use tier 2; Medium potential for human contact
- Single-family residential applications: A minimum 2-log reduction target is established for bacteria and protozoa. Minimum requirements for post storage treatment before use for non-potable reuse applications include 5 µm filtration upstream of the UV disinfection device and UV disinfection (16 mJ/cm2). The use of chlorine-based disinfection is not recommended due to the complexity of operation and design of these systems. Microfiltration or ultrafiltration of 0.5 µm is recommended.
- Multi-residential and non-residential applications: A minimum 2-log reduction target is established for bacteria and protozoa. Minimum requirements for post storage treatment before use for non-potable reuse applications include 5 µm filtration upstream of the UV disinfection device and UV disinfection (16 mJ/cm2), or chemical based disinfection with 1 µm absolute filtration and a CT for 2 log reduction for bacteria and at least 0.5 mg/L chlorine residual, or microfiltration or ultrafiltration of 0.5 µm with at least 0.5 mg/L chlorine residual.
- End use tier 3; High potential for human contact
- Single-family residential applications: A minimum 3-log reduction target is established for bacteria and protozoa. Minimum requirements for post storage treatment before use for non-potable reuse applications include 5 µm filtration upstream of the UV disinfection device and UV disinfection (30 mJ/cm2). The use of chlorine-based disinfection is not recommended due to the complexity of operation and design of these systems. Microfiltration or ultrafiltration of 0.5 µm is recommended.
- Multi-residential and non-residential applications: A minimum 3-log reduction target is established for bacteria and protozoa. Minimum requirements for post storage treatment before use for non-potable reuse applications include 5 µm filtration upstream of the UV disinfection device and UV disinfection (30 mJ/cm2), or chemical based disinfection with 1 µm absolute filtration and a CT for 3 log reduction for bacteria and at least 0.5 mg/L chlorine residual, or microfiltration or ultrafiltration of 0.5 µm with at least 0.5 mg/L chlorine residual.
For all tiers above, it is unlikely that pathogenic viruses will be present in harvested rainwater collected from surfaces above ground. However, sewage contamination is possible if harvested rainwater is stored underground, and for those cases, a 4-log reduction of viruses is required (CSA/ICC, 2018). The Illinois Extension (2020) provides guidance on mosquito prevention in rain barrels, including utilizing screens and regularly cleaning barrels.
Additional context and definitions
In Illinois, homeowner associations are permitted to specify whether rain collection is allowed and if so, outline the location, design and architectural requirements of the systems (765 Ill. Comp. Stat. § 165/20).
The Green Infrastructure for Clean Water Act of Illinois (2010), defines rainwater harvesting for non-potable uses as “green infrastructure.” Illinois promotes rainwater harvesting systems through financial assistance grant programs for persons interested in implementing green infrastructure (SB1489 2010).
Onsite non-potable water reuse specifications
Summary of Illinois's Onsite Non-potable Water Reuse Specifications
| Recycled Water Class/Category | Source Water Type | Water Quality Parameter | Specification | Sampling/Monitoring Requirements (Frequency of monitoring; site/ location of sample; quantification methods)* | |
|---|---|---|---|---|---|
|
Onsite non-potable use at single-family residences where potential for human contact is low (e.g., fire safety system) |
Rainwater |
Viruses |
No treatment requirementa |
Not specified | |
|
Bacteria |
|||||
| Protozoa | |||||
| Onsite non-potable use at single-family residences where potential for human contact is medium (e.g., water closets; urinals) | Rainwater | Viruses | No treatment requirementa | Not specified | |
| Bacteria | 2 log reduction | ||||
| Protozoa | 2 log reduction | ||||
| Filtration prior to UV disinfection | ≥5 µm | ||||
| UV disinfection | 16 mJ/cm2 | ||||
| Microfiltration or ultrafiltration | 0.5 µmb | ||||
| Onsite non-potable use at single-family residences where potential for human contact is high (e.g., spray irrigation) | Rainwater | Viruses | No treatment requirementa | Not specified | |
| Bacteria | 3 log reduction | ||||
| Protozoa | 3 log reduction | ||||
| Filtration prior to UV disinfection | ≥5 µm | ||||
| UV disinfection | 30 mJ/cm2 | ||||
| Microfiltration or ultrafiltration | 0.5 µmb | ||||
|
Onsite multi-residential and non-residential non-potable use where potential for human contact is low (e.g., fire safety system) |
Rainwater |
Viruses |
No treatment requirementa |
Not specified | |
|
Bacteria |
|||||
| Protozoa | |||||
| Onsite multi-residential and non-residential non-potable use where potential for human contact is medium (e.g., water closets; urinals) | Rainwater | Viruses | No treatment requirementa | Not specified | |
| Bacteria | 2 log reduction | ||||
| Protozoa | 2 log reduction | ||||
| Filtration prior to UV disinfection | ≥5 µm | ||||
| UV disinfection | 16 mJ/cm2 | ||||
| Filtration prior to chemical-based disinfection | 1 µm absolutec | ||||
| Disinfection | CT for 2 log reduction for bacteria and at least 0.5 mg/L chlorine residualc | ||||
| Microfiltration or ultrafiltration | 0.5 µmb with at least 0.5 mg/L chlorine residual | ||||
| Onsite multi-residential and non-residential non-potable use where potential for human contact is high (e.g., spray irrigation) | Rainwater | Viruses | No treatment requirementa | Not specified | |
| Bacteria | 3 log reduction | ||||
| Protozoa | 3 log reduction | ||||
| Filtration prior to UV disinfection | ≥5 µm | ||||
| UV disinfection | 30 mJ/cm2 with at least 0.5 mg/L chlorine residual | ||||
| Filtration prior to chemical-based disinfection | 1 µm absolutec | ||||
| Disinfection | CT for 3 log reduction for bacteria and at least 0.5 mg/L chlorine residual | ||||
| Microfiltration or ultrafiltration | 0.5 µmb with at least 0.5 mg/L chlorine residual | ||||
Source = CSA/ICC (2018)
* 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.
a It is unlikely that pathogenic viruses will be present in harvested rainwater collected from surfaces above ground. Sewage contamination is possible if harvested rainwater is stored underground, and for those cases, a 4-log reduction of viruses is required (CSA/ICC, 2018).
b Pre-filters of 5 to 100 µm should be used to extend the life of the filter.
c Due to potential for growth of opportunistic pathogens in plumbing systems (e.g., Legionella, Pseudomonas aeruginosa and Mycobacterium avian complex), a chlorine residual of at least 0.5 mg/L shall be maintained.
Upcoming state law or policy
No upcoming onsite non-potable water reuse regulations related to rainwater were found for Illinois.
References:
Canadian Standards Association (CSA) B805/International Code Council (ICC) 805. 2018. Rainwater Harvesting Systems.
Clean Water Act. 33 U.S.C. §§ 1251 et seq.
Homeowners’ Energy Policy Statement Act, 765 Ill. Comp. Stat. § 165/20.
Illinois Extension. 2020. Don’t get bugged; eliminate mosquito breeding habits.
Illinois Register. 2018. Subpart O: Harvesting Water Systems.
Illinois Senate Bill 38 (SB0038). 2012. Amendments to the Illinois Plumbing License Law.
Illinois Senate Bill 1489 (SB1489). 2010.
Please contact us at waterreuse@epa.gov 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.