Compostable Materials Odor Complaint Investigations

The local enforcement agency (LEA) is lead for enforcement regarding odor complaints at compostable material handling sites unless the site is specifically excluded from California Department of Resources Recycling and Recovery’s (CalRecycle) compostable materials regulatory requirements by 14 CCR Section 17855. Solid waste management enforcement programs are primarily carried out through local enforcement agencies (LEA) and the CalRecycle acting as the enforcement agency (EA). LEAs are designated by the governing body of a county or city and upon certification by the CalRecycle are empowered to implement delegated CalRecycle programs and locally designated activities.

Any activities that are excluded are under the jurisdiction of the local Air District. This includes when materials are handled in such a way as to preclude their reaching temperatures at or above 122 degrees Fahrenheit (14 CCR 17855(a)(5)(J), and/or when accumulated will not become active compost (14 CCR 17852(a)(11)) are under the jurisdiction of the local Air District.

Pursuant to 14 CCR, Section 18102, EAs may investigate excluded activities to verify that the activity is being conducted in a manner that qualifies as an excluded activity or to take any appropriate enforcement action. EAs may also use local nuisance and code enforcement laws, Health and Safety, Penal, or Civil Codes, or refer the odor complaint to the Air District.

When developing a compliance and enforcement strategy for responding to odor complaints, the EA should consider incorporating the following elements:


Odor Violation Verification

Verification of an odor violation is one of the most important and also one of the most difficult parts of an odor complaint investigation. The inspector should respond immediately to detect and verify that the odor exists where the complaint originated. Odors can often dissipated by the time an inspector arrives on the scene due to changes in wind direction and air pressure, dilution of the odor and mixture of odors from other nearby sources. Complaint investigations should take priority over any other routine work.

Because the verification of an odor violation is extremely complex, the complainant may become frustrated with the enforcement agency. Unpleasant odors can be a very emotional issue with the complainant when it is felt that their quality of life is being negatively impacted. The compostable material site’s 24 hour phone number for odor complaints should be provided to complainants. The complainant should be encouraged to call the operator directly as well as the enforcement agency if an odor event occurs again. The complainant needs to know that their input is valuable and necessary to assure that off-site odor incidents do not occur. It is well known that odor impacts will destroy a composting site because the community will not allow a nuisance site to exist in their neighborhood.

Some agencies rely on information provided by the public to determine if a violation has occurred, such as the duration, frequency, intensity, and quality of the odor, in addition to the time of day and the number of complaints received. Sometimes, even just one ‘verified’ complaint can be enough to cite a violation. Examples of other agencies’ comprehensive odor complaint investigation procedures and other odor investigation tools are provided below.

Reliable methods of detection and verification include field odor detection devices, an odor panel, or the inspector’s nose. Even if the odor is not verified off-site, the odor complaint investigation should include review of all handling and storage activities and weather conditions at the time of the reported odor occurrence.

The OCAP (Operational Challenges Assessment Procedure) was designed to assist in site evaluation to mitigate odor caused by on-site operational practices.

Odor Monitoring Circuits

Implementing a routine odor monitoring circuit by the operator and/or inspector can provide information about potential nuisance odors before any complaints are received. Periodically checking the site and surrounding neighborhood for odors for can also provide early detection of inadequate compostable material handling practices. However, odor monitoring will not prevent odor complaints in all cases.

One LEA has provided an example of an odor monitoring circuit procedure as a possible framework for other enforcement agencies.

Agency Coordination of Complaint Referrals

The California Environmental Protection Agency recommends an approach whereby the EAs and Air Districts develop working relationships to investigate, and coordinate inspections regarding odor complaints. If the complainant(s) alleges that the odor is causing an illness, the EA/Air District should also refer and coordinate the complaint investigation with the local Health Department.

EAs should consider preparing a list of all known compostable material handling facilities and operations for their local Air District to facilitate the Air Districts referral of composting odor complaints to the EA. Complaints received from Air Districts should be documented and investigated. If the EA has received an odor complaint and it is determined to have originated from an activity that is not a compostable material handling operation or facility, the EA should immediately refer the complaint to the local Air District. EAs are encouraged to contact Air Districts since Air Districts may have additional knowledge of odor minimization and/or verification techniques and some Air Districts may also have the ability to provide the EA with laboratory analysis of odorous air emissions. Additionally, the enforcement agency should maintain a separate log of odor complaints and referrals.


Below are some links to other agencies’ odor violation standards and/or odor complaint investigation protocols and on-line complaint form examples.

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