What type of drilling does the Mendocino County CUPA program permit?
Mendocino County Environmental Health permits the drilling of borings (including geotechnical) and monitoring wells.
What is the difference between a monitoring well and a boring?
Mendocino County recognizes the definition provided in the California Well Standards “Bulletin 74-90”, as well as “A Working Draft Revision of California Department of Water Resources” dated September 2013. The county recognizes a monitoring well to be a well that is used for the purpose of monitoring groundwater, saturation, slope, or for vertical profiling. Borings or exploration holes are temporary holes in which water, soil, or soil vapor sample(s) are collected immediately on site. Often borings are grouted the day of construction, or the following day. Under Title 16 Mendocino County Code section 16.04.020 exploration or boring holes are included in the definition of monitoring wells.
Do I need a permit for Geotechnical drilling?
In general, Yes! However, Mendocino County does not permit Geotechnical borings if the hole is less than twenty feet, is not in a known or suspected of contamination, and an aquifer is not penetrated. Should the aquifer become penetrated (regardless of the depth), a permit shall be required. If the aquifer is found during the drilling process, the permit shall be obtained no later than five working days following the completion of the work. Final approval will not be granted until well/boring logs are submitted showing a proper seal.
What do I need to submit with the drilling permit application?
- Fees in accordance with adopted fee schedule.
- A site map to scale including a north arrow, approximate property lines, existing & historic site features, existing wells (if applicable), existing septic tanks and leach fields (if applicable), underground storage tanks and fuel lines (if applicable), and any other pertinent existing & historic features and information.
- All applications are to be properly completed, and shall be typed, computed, or written in ink.
- A signature of a licensed C-57 driller.
- Signature could be wet with the date, or an electronic stamp with the date, time and name of the driller.
- A work plan describing the proposed well configuration and drilling and construction/destruction methodology. For our purposes the term “Scope of Work” is synonymous with “Work Plan”.
- An encroachment permit from the appropriate authority if the drilling takes place in any public roadway and/or impedes/impacts the flow of traffic.
- A written access agreement from property owner(s), whose properties are being encroached on by the investigation.
Do I need to schedule with Environmental Health for an inspection?
Yes. Mendocino County inspectors should be consulted for scheduling of inspection at a minimum of five days prior to drilling activities. The scheduling of inspection is to be completed after the permit is issued.
6. Is Pressure Grouting permitted for abandonment of monitoring wells?
No in almost all cases. Due to multiple pressure grouting failures Mendocino County is no longer allowing pressure grouting except in cases where immediate risk of electrocution, damaging neighboring wells or pipes, or all other means of access have been exhausted. In those cases, the inspector shall determine if pressure grouting in those instances is an acceptable and appropriate practice. If so, all well casing must remain intact (as built) and pressure must be able to be measured at the wellhead to a minimum standard of 25 psi for 5 minutes. Prior to the placement of grout, wells must first be put under pressure to determine the casing and/or wellhead have been compromised.
7. Do I need a Coast Development Permit?
Coastal Development Permits (CDP) may apply when constructing monitoring wells and borings on the Mendocino County coastal region. The requirement determination is made by authorized agencies of the California Coastal Commission. All projects on the coast will be vetted to determine the appropriateness of a CDP prior to issuing the monitoring well permit. The process may delay the issuance of the monitoring well permit.
8. What is MS-4 Storm Water, and does it apply to monitoring wells?
A MS-4 is a conveyance (or system of conveyances) that is publicly owned entity which discharges to waters of the United States. It includes storm drains, pipes, ditches, etcetera, that is not a combined sewer, and is not part of a publicly owned sewage treatment plant. Operators are required to develop and implement a comprehensive Storm Water Management Program (SWMP) which shall include pollution prevention measures, treatment or removal techniques, monitoring, use of legal authority, as well as other appropriate means to control the quality of storm water discharged from the MS4 to the Maximum Extent Practicable (MEP).
Monitoring well permits may be subject to the Municipal Separate Storm Sewer Systems (MS4s). Work conducted within the city limits of Fort Bragg, Point Arena, Ukiah, and Willits are overseen by the applicable city. For projects outside the city limits, contact the inspector who can determine if the monitoring well project falls within the MS-4 storm water regulations. Providing the parcel number to the inspector may assist in a more rapid determination. If the project falls within the MS-4 waste water area, a Construction Site Storm Water Runoff Control Checklist and a Well Drilling and Sediment Control Plan are required.
9. Can I use Bentonite?
Bentonite is an absorbent clay that is commonly used to seal monitoring wells because of its superior swelling characteristics and low permeability. Bentonite is available in the form of chips, pellets, powder, and gel. Bentonite powder or gel can be added to neat cement up to 5% of the grouting slurry of the monitoring well or boring. When not in a cement slurry, Bentonite shall be hydrated and must set prior to completion of the well seal. Although pellets are the preferred form of Bentonite, chips are allowed provided they are no larger than 1/5 the radial thickness of the annular space.
10. Are governmental agencies exempt from the permitting requirements?
No. Monitoring wells apply to all parties regardless if it is private or public, unless otherwise exempted in the applicable code. If a governmental agency believes they are exempt, they must provide codification of the exemption to the inspector prior to conducting work.
11. Do I need a County Business License?
All businesses conducting their trades in the unincorporated areas within Mendocino County are mandated to have a Mendocino County Business License. This includes both the drillers and the consultants. Permit applications will not be processed for unincorporated areas if either the driller or consultant, or both, does not have a current business license. For further information on the business licenses, you can contact the Mendocino County Tax Collector’s Office at 707-234-6875 or visit their website.
12. What if I have a project that covers different APNs/parcels in one project?
Mendocino County Environmental Health understands that projects often time require several properties or APNs to be covered during the same project. It is for that reason each APN is required to have its own permit. However, the billing will be per project. For example if you have five wells covering three APNs, it would be the same price as if the five wells were on the same property. The only difference is that each APN would need its own permit and access agreement (if applicable).