Ask the Expert: What does the DEQ rule change mean for recycled (or reclaimed) water?

by Brett Moore, P.E., Senior Engineer

The DEQ has proposed modifications to the recycled water, or reuse, rules for treated wastewater. These rules could affect many municipalities and their systems. In general, however, the rules provide greater flexibility to the DEQ by allowing for a broader beneficial reuse of treated wastewater effluent. Some modifications to the rules will entail greater restrictions on setback requirements for some facilities currently irrigating with reclaimed water. At this time, it has not been indicated how or when existing facilities may need to comply with these modifications.

In other situations, the rules clarify how systems may be operated for certain types of crops, for which uses the systems may apply, what harvest restrictions and/or pasturing may be allowed, and when harvest and/or pasturing may be allowed after the last application of treated wastewater.  In general, the reuse rules provide greater clarity to municipalities regarding how to beneficially use their wastewater and under what parameters they may operate their systems. A new addition to the reuse rules is the beneficial use of reclaimed wastewater in wetland environments.

How can wetlands be used for reclaimed water at a municipal wastewater treatment facility?

In 1992, AP partnered with the City of La Grande to prepare a pilot study for using treated wastewater effluent in a wetland environment. Significant groundwater monitoring has taken place over the last 16 years, and successful results have been achieved.

In 2002, AP assisted the City of La Grande and worked in conjunction with the Oregon Department of Fish and Wildlife (ODFW) and other agencies on a project to restore Tule Lake at the Ladd Marsh Wildlife Management Area, which is owned and operated by ODFW, by applying reclaimed water to the wetland. This project has been a significant success, with ongoing monitoring of surface water quality and groundwater quality showing definite beneficial effects. Wildlife response has also been significant. This wetland reuse project won several awards from state and national organizations.

With recent changes to the reuse rules that allow wetlands to be used for disposal of reused water, the alternative explored at Tule Lake becomes more attractive to many municipalities and organizations. The reuse rules authorize water reuse in natural wetlands, reclaimed wetlands, and constructed wetlands in upland areas. Before developing a reuse project, several water quality parameters must be met in order to protect surface water, public health, and groundwater quality. Appropriate siting of the wetland is needed to ensure that a viable wetland can be constructed.  Also, certain treatment elements must be achieved in the wastewater facility to protect groundwater. Local geology may also come into play and affect the type of facility that can be constructed on any given site.

Although wetlands may not be a viable alternative for all wastewater treatment facilities, they may be able to provide your system with a beneficial, cost-effective way to treat and dispose of wastewater effluent.