Wastewater and Reclaimed Water Spills
The use and disposal of wastewater and reclaimed water within Maricopa County is governed by the rules and
regulations of the Maricopa County Environmental Health Code.
Chapter 2, Section I, Regulation 2, Subsection B of the code requires that:
“Sewage, reclaimed wastewater, refuse, human excreta, or other wastes shall
not be placed or deposited into any waters of the County or upon or under any land within the County, except as approved by the Department and
in accordance with the provisions of the Arizona Administrative Code, Title 18, Chapter 9, Section C305 including all revisions, technical
corrections, and supplements published as of November 12, 2005.”
With the exception of a wastewater collection system operating with a Capacity, Management, Operation and Maintenance (CMOM) Permit, all
releases of wastewater or reclaimed water to non-permitted areas are considered to be spills by the Maricopa County Environmental Services Department (MCESD).
If a wastewater or reclaimed water spill occurs it must be reported to the Maricopa County Environmental Services Department by the operator of the wastewater
or reclaimed water system/facility and clean-up and remediation efforts must be implemented as described in the sections below.
If you are not the operator of a wastewater or reclaimed water system or facility but wish to notify the MCESD of a wastewater or reclaimed water spill, please
call the MCESD’s Complaint Line at (602) 506-6616 or file a complaint online as instructed on the
Submit Complaint page. The status of a previously submitted complaint can be checked on the
Track Complaint page.
Actions Required When a Spill Occurs
When a wastewater or reclaimed water spill occurs, the following actions should be taken by the operator:
- Stop the spill by isolating the source of the spill.
- Contain the spill. This may require the construction of temporary earth berms or dams.
- Call for assistance (other operational staff or utilities as required).
- Implement immediate short term clean-up including pumping and proper disposal of the spilled material
and disinfecting the affected area. If necessary, quarantine the affected area to prevent access by the
general public until the spill has been remediated.
- Notify the relevant regulatory agencies of the spill (Arizona Department of Environmental Quality,
Maricopa County Environmental Services Department, municipalities, other utility companies, etc.).
- Implement the long term clean-up activities (disinfection, fecal coliform testing of the soil and/or soil removal) as necessary to remediate the spill.
- Submit a written report to the MCESD within 14 days. The activities associated with the above actions and a post mortem analysis of the cause of the spill should be described in detail in the written report.
What is a critical wastewater or reclaimed water spill?
A critical spill is the spill that is an “imminent and substantial threat to public health or the environment” or was the result of a major failure of a utility’s infrastructure.
When determining if a wastewater or reclaimed water spill is a critical spill, the operator should consider:
- The location of the spill.
- The severity and volume of the spill.
- The size of the contaminated area.
- The risk to the general public.
Spills that backup into residences or buildings and spills that affect businesses associated with a high level of public health risk such as food establishments, nursing homes or medical
facilities should typically be considered to be critical spills. Spills that are the result of a major failure of a utility’s infrastructure, such as the failure of a reclaimed water or sewer
line or a problem with a lift station or treatment facility, should be considered to be critical spills. Assume that the spill is a critical spill if there is any doubt.
Spill Notification Procedures
The Maricopa County Environmental Services Department must be notified immediately by the operator when a wastewater
or reclaimed water spill occurs. A Spill Notification Form must be filled out and sent by facsimile
to (602) 506-6925 or e-mail to the Water and Wastewater Treatment Program at
If a spill occurs during normal business hours (Monday - Friday, 8 a.m. - 5 p.m.), AND the spill is a
critical spill follow-up your e-mail facsimile notification with a telephone call to the Water and Wastewater
If a spill occurs after normal business hours or on a holiday, AND the spill is a critical spill
please follow-up your fax or e-mail notification with a telephone call to the MCESD's Call Center (Complaint Line)
at (602) 506-6616. Navigate through voicemail menus '1' and '8' and then leave a message with your name, utility name,
callback telephone number, details about the spill and identify the spill as a critical spill. The on-call MCESD staff
member should telephone you back within 20 minutes. The on-call MCESD staff member will assess what action(s) may be
required in response to the spill.
Spills located on private property AND not a result of the failure of the utility’s infrastructure should
be reported to the Call Center. A Spill Notification Report does not need to be submitted for this case.
A Spill Reporting Decision Tree Diagram is available to assist in understanding
when a Spill Notification Report should be submitted.
Spill Remediation Requirements
The area where the spill occurred must be restored to its original pre-spill state. Remediation actions may include disinfection,
fecal coliform testing of the soil and/or soil removal. Typical disinfectants used are powdered chlorine, liquid chlorine or lime.
Samples of soil from the remediated spill area must have a fecal coliform count comparable to the unaffected soil in the immediate area.
Laboratory analysis documenting soils from the affected and unaffected areas should be included in the written spill report.
Remediation of soils may not be possible for spills that occur in streets. Spills that occur within buildings might require specialized
remediation procedures to ensure that the structure is safe to re-occupy.
Written Spill Report
A Written Spill Report should be submitted to the MCESD within 14 days after the date the spill occurred. This requirement may, at the
Department’s discretion, be waived for small non-critical spills. Also, a Written Spill Report may not be required for small spills from a
wastewater collection system operating under a Capacity, Management, Operation and Maintenance (CMOM) permit. A
Spill Reporting Decision Tree Diagram is available to assist in understanding when a Written Spill Report must be submitted to the MCESD.
The report must describe the cause of the spill, the actions undertaken to remediate the spill, supporting documentation detailing the remediation
effort, the preventative measures and operational and maintenance procedures that have been implemented to prevent a repeat spill in the future, and
any other relevant documentation or data related to the spill.
If the spill was caused by a major failure of the utility’s infrastructure the written report should include a description of the action taken to
repair the problem, a post mortem analysis describing the cause of the infrastructure failure and a narrative describing how the problem will be prevented
from re-occurring in the future.
For critical spills, include photographs and laboratory sample analysis reports documenting that the spill has been properly remediated and/or failed infrastructure repaired.
Mail or deliver the spill report to:
Maricopa County Environmental Services Department
Water and Waste Management Division
Water/Wastewater Treatment Program
1001 N. Central Avenue, Suite 150
Phoenix, AZ 85004-1940
Water and Wastewater Treatment Program staff will review the Written Spill Report to determine if any additional remediation actions are required.
What does the MCESD do with spill reports?
The Spill Notification Report is used by the MCESD to:
- Assess the criticality of the spill and determine what if any immediate actions are required by the MCESD in response to the spill.
- Document the spill location and cause to determine if there is a pattern of repeated spills at a particular location or due to a specific cause.
- Document the frequency and types of spills to determine if there may be operation or maintenance issues that need to be changed or new procedures implemented so as to prevent future spills.
The Written Spill Report is used by the MCESD to:
- Document the remediation actions that occurred in response to the spill.
- Perform a post mortem analysis of the root cause of the spill to determine if there is any systemic design, operations or maintenance issue(s) that need to be addressed.
For example, is there an issue that requires re-design of sewer collection system infrastructure, is preventative maintenance being performed to address a corrosion problem, does
a Fat, Oils and Grease (FOG) program need to be implemented by the utility?
- Notify other utilities of discovered problems that may affect their infrastructure.
- • Incorporate ‘lessons learned’ into the MCESD’s Approval To Construct/Approval Of Construction plan review process so that new infrastructure will be designed to address observed
design, operational and maintenance problems that resulted in spills.
Wastewater Collection Systems Operating with CMOM Permits
Some wastewater collection systems operate under Capacity, Management, Operation and Maintenance (CMOM) permits in accordance with the provisions of the Arizona Administrative Code (AAC), Title
18, Chapter 9, Section C305. A CMOM permit is issued by the Arizona Department of Environmental Quality (ADEQ) and allows a permittee to manage, operate, and maintain a wastewater collection system
under the terms of an approved CMOM Plan.
Some characteristics of CMOM permits that affect Sanitary Sewer Overflow (SSO) reporting:
- Wastewater spills of less than 50 gallons do not have to be reported.
- Wastewater spills between 50 – 2,000 gallons only have to be reported if there is an “imminent and substantial threat to public health or the environment”.
- Wastewater spills greater than 2,000 gallons must be reported.
The definition of “imminent and substantial threat to public health or the environment” is defined in AAC R18-9-C305(A). Refer to the AAC for additional details about the
specific rules and regulations governing CMOM permits.
Although the MCESD is not delegated CMOM permitting responsibilities by the ADEQ, the Maricopa County Environmental Health Code (MCEHC) recognizes CMOM permits as related to
wastewater spills as noted in Chapter 2, Section I, Regulation 2b of the MCEHC. If a utility is operating under a CMOM permit a Spill Notification Report and a Written Spill Report
is required to be submitted to the Treatment Program:
- For critical wastewater spills between 50 – 2,000 gallons.
- For all wastewater spill greater than 2,000 gallons.
Wastewater spills of less than 50 gallons do not have to be reported.
Please note that the CMOM permit requires that all critical spills greater than 50 gallons but less than 2,000 gallons and all spills greater than 2,000 gallons must be recorded
and submitted in an annual report to the ADEQ. The MCESD requires that a copy of this annual report be submitted to the Treatment Program.