All Exceptions require additional documentation. See I06 Exception Documentation Summary Table.
WT-003 Municipal Potable Water Supply
If health or utility regulations require a project to use municipal potable sources, it is allowed, but only for potable uses including sinks, faucets, janitorial uses, and showers. Non-potable uses such as toilet flushing, clothes washing, irrigation, and equipment uses must use water sourced from the project site. While it is not required, the project is encouraged to include full rainwater harvesting capacity in anticipation of future regulatory acceptance of additional rainwater use.
To use this Exception, the project team must meet the following minimum advocacy requirements:
- Complete a Water Reuse Permit Map spreadsheet for the site’s AHJ (scroll down to Permit Map Instructions and Spreadsheet under On-site Water Reuse Permit Map on this page of the ILFI website); and
- Hold a minimum of two meetings with at least one representative from the AHJ and representatives from at least two of the following other departments to review the results of the permit map research activity and request a permit pathway for the proposed on-site systems that meet the requirements of the Water Petal.
- Plumbing Inspectors
- Department of Health (at County and/or State level)
- Drinking Water Division
- Wastewater Division
- Department of Environmental Health, Environmental Quality, or Ecology
- Water and/or Sewer Utility
- Other relevant entities as appropriate
Note that a fully designed system is not required to meet the minimum advocacy requirement, but should be developed if there is a type of system that may be acceptable to the AHJ.
The intent of the first meeting is to provide information about the types of systems being proposed for the project, cite other jurisdictions in which they have been approved and installed, and identify barriers evident in the Water Reuse Permit Map. The second meeting is intended to propose general design solutions, address questions and concerns raised in the first meeting, and present other data as requested (e.g., code precedence, performance data, contacts from jurisdictions where the systems have been installed). If the project team is still unable to permit their systems after these efforts have been completed, they have fulfilled the advocacy requirements and may connect to the relevant municipal systems.
More information about the permit maps and permitting assistance can be found in ILFI’s Water Petal Permitting Guidebook.
WT-004 Municipal Water for Fire Protection
A connection to a municipal water supply is allowed for fire protection systems, as long as the connection is dedicated only for fire protection, and does not supply water for any other uses.
WT-005 Chemical Disinfection
Use of the chemicals listed below is allowed if required by the authority having jurisdiction. In all cases, the amount of chemical added must be the minimum allowed by the jurisdiction.
Project teams using this exception will need to provide evidence that the treatment is required by the jurisdiction having authority, identify required concentrations, and provide a narrative with diagrammatic description of the treatment system, including operation details demonstrating that only the minimum quantity of chemical allowed by code is being used, and that concentrations otherwise meet requirements as indicated in the specific exception requirements for each chemical.
The following additional requirements apply for each allowed chemical:
Chlorine
The project must include and document point-of-use dechlorination with a 0.5-micron carbon block filter or other approved dechlorination method for all potable end uses.
Hydrogen Peroxide
Where treatment is required to be added at the point of storage, and the storage container has an overflow outlet, residual concentrations of the hydrogen peroxide must be dissipated prior to release of the overflow into any non-treatment aquatic habitat. Documentation of the water system must address, with written confirmation by the system designer, how the hydrogen peroxide breakdown will occur prior to overflow dispersal into aquatic habitat.
WT-006 Municipal Sewer Overflow Connections
If health or utility regulations require an overflow connection to the municipal sanitary sewer system, it is allowed if the project team:
- Advocates for an exemption to the authority having jurisdiction.
- Installs a manual valve control that is designed to remain closed.
- Provides a signed statement that the overflow connection was not used during the performance period.
WT-007 Periodic Large Events
If a project hosts infrequent events (e.g., 3–4 days annually) that significantly exceed the facility’s typical volume of visitors, portable toilets and supplemental water may be used for those events. The project’s sewer management and potable water system must be sized appropriately for the rest of the year. The project team must provide an explanation of the event capacity needs and the alternatives explored in an effort to avoid needing this Exception.
WT-008 Scale Jumping Within An Aquifer
Use of this exception requires approval from ILFI in advance. See details below.
Scale Jumping within an aquifer is allowed for projects where:
- Water capture and reuse, including rainwater harvest and greywater recycling, have been maximized (legally and technically).
- Water use has been minimized (best-in-class fixtures and demand-minimizing strategies).
- Ground/well water is not accessible due to contamination, or technical or legal reasons.
Additionally, the project team must be able to meet the following conditions:
- Show that the water is extracted from the same local aquifer serving the project site.
- Provide a water balance showing that the extracted water, minus evapotranspiration and consumption, will infiltrate back into the same aquifer.
- Include all pumping energy in the energy balance for the project.
The project team must request approval in advance through a Request for Ruling. The submission must explain how all eligibility criteria and conditions have been met and include calculations, diagrams, and maps demonstrating compliance.
The same metering and performance documentation required for onsite sources apply. Pump energy must be reflected in I07 Energy + Carbon Reduction (C4) consumption calculations (See Project Energy Needs Clarification).
WT-009 Municipal Sewage Treatment for Affordable Housing
Use of this exception requires ILFI approval in advance; see details below.
Multifamily affordable housing projects of three stories or more are allowed to connect to a municipal sewer system for sewage treatment. Single story and two story affordable housing projects may also use this Exception on a case-by-case basis. Project teams facing density, regulatory or other barriers for on-site sewage treatment must make their case through a Request for Ruling and receive preapproval from the Institute in order to obtain an exemption and connect to the municipal sewer system.
