Sanitary Survey Information for Public Water Systems

Which facilities will be surveyed?

During the sanitary survey, the following facilities will be surveyed:  

• All water sources including wells, surface water intakes, and consecutive connections
• Pumping control facilities
• Treatment facilities including well entry points and treatment plants
• Water storage facilities including tanks, ground reservoirs, and elevated towers
• Distribution systems including booster stations

What records will be reviewed?

As part of the sanitary survey, the following records will be reviewed:

• Previous sanitary survey reports
• Previous sample results and compliance records
  • Monitoring history, future monitoring schedule, waiver status
• Sample site plans (total coliform/bacti, Disinfection Byproducts (DBPs), Water Quality Parameters (WQP), lead/copper, etc.)
• Water system inventory
  • Source information including construction, pumping rates, design and emergency capacity, well static and drawdown levels
  • Treatment information including pumping rates, design and emergency capacity, treatment objectives and processes, schematic of treatment process
  • Storage information including type and size of storage facilities
  • Distribution system information including, maps, pressure zones, booster stations, mains, hydrants, valves, meters, service lines
  • Contacts and current operators including certified water operator credentials
  • Population and service connections
  • Production totals including average use and highest day
  • System class points and classification
• Standard Operating Procedures (SOP) manuals and records
• In house water quality monitoring logs and related SOPs
• Operation and maintenance manuals and records
• Distribution system 
  • Hydrant flushing/valve exercising program
  • Water loss audit and/or records
  • Main break log
• Cross connection control program
• Security measures and cybersecurity self-assessment
• Asset Management Plan
• Emergency Action Plan and Drought Contingency Plan
• Customer complaint log

Required Record Retention Time

The surveyor and representative(s) of the PWS will walk through the water system from source to distribution and physically evaluate facilities (See Table: Sanitary Survey Elements and Descriptions) along the way. The surveyor will ask questions and make observations about the public water supply and operation, maintenance, and monitoring of the water facilities. The surveyor may also collect water samples including total coliform samples and chlorine residuals from the source, entry point, and/or distribution system.

The sanitary survey can take a couple hours to a few days depending on the system size and complexity. Expect to submit requested documents to the surveyor before or after the on-site inspection. When your sanitary survey is scheduled, the surveyor will give you an estimate of the time required.

What are the elements of a sanitary survey?

The eight elements of a sanitary survey are described in the following table. Surveys of NWS and some CWS will also include a review of Wellhead Protection and an update to the Inner Wellhead Management Zone (IWMZ) information.

Sanitary Survey Elements and Descriptions

What are the goals of a sanitary survey?

The goals of a sanitary survey are to:

1. Identify and address deficiencies to ensure the production and distribution of safe drinking water.
2. Provide MDH’s assistance to the system.
3. Produce a consistent and informative report that will identify compliance and technical issues at the system.
4. Accurately document the system’s inventory and needs.
5. Foster a positive relationship between MDH and the drinking water system.

What should be done with the report?

Sanitary survey reports contain findings identified by the surveyor. Findings may be recommendations, requirements, deficiencies, or significant deficiencies. It is the responsibility of the PWS to address any findings that are identified.

Sanitary survey reports must be maintained by the PWS for at least 10 years.

What are the types of findings in the report?

There are four types of findings that may be identified as part of a sanitary survey.

1. Significant Deficiencies: include, but are not limited to, defects in design, operation, maintenance, administration or failure or malfunction of a system component including sources, treatment, storage, or distribution system that are causing, or have potential to cause, the introduction of contamination into the water delivered to consumers.
2. Deficiencies: are observed or identified issues that may indicate noncompliance with regulations, codes, or drinking water standards, result in contamination of drinking water delivered to consumers, or compromise to public health.
3. Requirements: are based on regulation, code, and standard operating procedures across the water industry to be followed to maintain the public water supply and are listed as informational guidance.
4. Recommendations: best practices for a public water supply to maintain the safe delivery of drinking water to consumers.

What are the expectations of findings in the report?

Requirements not addressed before the next survey (18 months for community, 3 years for noncommunity) may be elevated to deficiencies.

Deficiencies must be corrected in a timely manner. The surveyor will work with the PWS to clearly identify a correction timeline for each deficiency identified.

Significant deficiencies must be corrected within a state approved time frame. A specific cover letter will accompany the sanitary survey report highlighting the significant deficiency. The determined corrective action must be completed by the PWS within 120 days of receiving the sanitary survey report unless an approved corrective action plan is in place that extends this time frame. Failure to correct a significant deficiency within the specified time frame results in a treatment technique violation.

All public water systems supplying groundwater must manage the land adjacent to their wells. The 200-foot radius around the well is the Inner Wellhead Management Zone (IWMZ). IWMZ work includes completing a Potential Contaminant Source Inventory (PCSI). The main purpose of a PCSI is to identify actual and potential sources of contamination within the IWMZ and to verify the distance and location of each contaminant source relative to each public water supply well.

MDH conducts a IWMZ PCSI survey with public water suppliers during the wellhead protection planning process (for community systems) or during a sanitary survey (for noncommunity systems). A knowledgeable representative from the public water supply should be present when the IWMZ PCSI is being completed to answer questions that may arise. For example, questions relating to land use on a neighboring property; location of buried sewer lines/septic system components; location of buried fuel oil tanks; location, use and/or storage of fertilizers and other chemicals; and disposal of hazardous products are questions that may need to be answered.

The results of the IWMZ PCSI are in the wellhead protection plan or the sanitary survey. Public water suppliers who have had a IWMZ survey conducted must:

• Maintain the isolation distances defined in the state Well Code (Minnesota Rules, Chapter 4725) for proposed potential sources of contamination.
• Monitor existing potential sources of contamination that do not comply with the isolation distances defined in the state Well Code.
• Implement wellhead protection measures for potential contaminant sources within the IWMZ.

To determine whether an IWMZ PCSI has been completed at a specific public water supply, check out the status report at the MDH Public Water Supply Program web page .

For information on potential contaminant sources, isolation distances, and sensitive wells, refer to the Rules Handbook: A Guide to the Rules Relating to Wells and Borings (PDF) at the MDH Well Management Section, Wells and Borings Laws and Rules web page.

The list below illustrates commonly found items that must be addressed as part of a sanitary survey. This list is not all-inclusive.

Source

• Broken or missing electrical conduit for wires serving a submersible pump
• Missing bolts, nuts, vent, vent screen, seal/plug around sounding tube or other open hole leading directly into the well
• Loose or missing well cap
• Area around the well not graded to divert water away from the casing

Pumps/Pump Facilities & Controls

• Missing check valve and/or missing air/vacuum relief valve
• Check valve stuck open (sample tap upstream of check valve has pressure without well pump running)
• Air/vacuum relief discharge not 18” above floor and/or missing screen
• Missing water meter for well

Treatment

• Cross connections – missing or outdated service tag on device, improper air gap on backwash discharge
• Chemical feed – chemicals are not ANSI/NSF approved, pumps not maintained/inoperable/leaking, storage tanks not labeled, no secondary containment, expired testing reagents, missing vents/vent screens
• Gas Chlorine – exhaust fan inoperable, missing cylinder restraints, panic hardware on door, and/or leak detection
• Aerator intake and exhaust not properly screened

Storage

• Missing or damaged screens for vents or overflows
• Missing overflow
• Hatches or doors not locked
• Hatch covers missing gaskets

Distribution

• Unprotected cross connections – private wells, industry
• Dead ends
• No routine flushing
• Low chlorine residuals
• Watermains smaller than 6 inches

Monitoring/Reporting and Data Verification

• Improper bacteria sampling sites – using wellhouse, not having adequate number of sites, not rotating throughout all approved sites each monitoring period
• Inadequate record keeping

Water System Management

• Missing cross connection control program or testing program for backflow prevention devices
• Missing asset management plan
• Missing emergency response plan
• New – Failure to complete a cybersecurity assessment and certification form.
• Incomplete plan submission

Operator Compliance with State Requirements

• Expired certified water operator’s license
• Not contracting with or employing a properly certified water operator

Wellhead Protection

• Wellhead protection has not been updated

Drinking Water Protection

• Drinking Water Protection Section
• Restaurants, Resorts, Campgrounds (Transient)
• Schools, Offices, Factories, and Child Care (Nontransient)
• Community Public Water Supply
• Drinking Water Protection Contacts by Topic

Sample Collection/Site Plans

• Sample Collection Procedures
• Basics of Monitoring and Testing of Drinking Water in Minnesota
• Total Coliform Sample Collection Tips for Community Public Water Systems (PDF)

Emergency Response

• Emergency Response Guidance for Community Public Water Systems (PDF)
• Guidance for Responding to Water Main Breaks or Pressure Loss Events (PDF)
• Pressure Loss at Non-Municipal Community Public Water Systems (PDF)
• Community Public Water System Flooding Guidance

Funding

• Source Water Protection Grants
• Drinking Water Protection Forms
• Drinking Water Revolving Fund Forms

Water Operator 

• Water Operator Certification and Training
• Certification Frequently Asked Questions
• Exam Information
• Exam Study Materials
• Contract Operating Information
• Water Supply Systems and Wastewater Treatment Facilities: Advisory Council
• Laws and Rules: Drinking Water Operator Certification
• Minnesota Water Operator Training
• Renewal Requirements for Water Operator Certificates
• Relevancy of Training for Certified Water Operators

Lead and Copper Rule

• Lead and Copper Rule Revisions
• Lead and Copper Site Plan Updates

Cybersecurity

• Assessing Security of Public Water Systems
• Cybersecurity Assessment Certification Form (PDF)
• Cybersecurity Assessments (EPA)