In this article, we continue our discussion of the Top 10 most frequently cited significant deficiencies and violations to raise awareness and help operators identify and correct issues before they become a potential health threat or citations in a sanitary survey. At #2 in the Top 10, source construction deficiencies (S030) were cited 9% of the time during sanitary surveys for the 2022 inspection year and 9% in the 2023 inspection year. Groundwater wells are the most common sources of drinking water used in Colorado (70% of public water systems use groundwater wells) and are perhaps one of the most overlooked parts of water systems. Wells can go unnoticed for years since they are often located away from most activities and may only be noticed when the flow of water is altered. The most commonly discovered significant deficiencies with wells are related to electrical conduits, gaskets, vents and vaults.
What are the minimum standards for a properly constructed well? In the “State of Colorado Design Criteria for Potable Water Systems” (Policy DW005), CDPHE actually primarily refers to the Colorado Division of Water Resources’ (DNR) latest edition of “2 CCR 402-2 Rules and Regulations for Water Well Construction, Pump Installation, Cistern Installation, and Monitoring and Observation Hole/Well Construction” (a.k.a. Colorado Well Driller Regulations). The purpose of these regulations is to ensure public health and the safety of groundwater resources. The regulation outlines minimum construction standards for all types of wells in all types of environments, and it defines minimum well height, screening, minimum distance from potential sources of contamination, grouting standards, pump installation and much more.
There are many variations to well heads, but the two primary ones that inspectors come across are the “split-cap” and the “well-cap” (see image below for reference). The “split-cap” has the discharge line, vent and electrical conduit all protruding from the wellhead. The well head is comprised of two metal plates with a rubber gasket in between. When installed, the two plates are compressed, the rubber gasket expands and creates a watertight seal. The “well-cap” has a pitless water connection (below frostline) and a designated female electrical connection, a set of gaskets and a built-in vent (which are typically screened).
*photo courtesy of Oregon State University https://wellwater.oregonstate.edu/well-water/wells/well-check-list
Well head
Well heads must be designed and constructed at the top of well casings to prevent the entry of contaminants into the well. The majority of the wells that the department inspects are located outdoors and are exposed to the elements. It is vital that the wells are constructed and maintained in a manner that will protect the raw water. Some common issues that inspectors observe are missing/damaged gaskets, missing bolts, broken or loose well caps (bolts are missing or not tightened), split-caps not seated on the well casing properly and a split-cap with a rope (used to hold the well pump in position or to assist in pulling the pump out) coming out of the well that is not properly sealed.
The split-cap well head was not properly sealed to the well casing. The supplier applied caulking between the split-cap and the well casing.
The bottom of the well head cap was broken and did not allow for a tight seal. A new well head was installed.
Well Vents
Vents are an integral part of a well as they permit air to freely enter and exit the well. Vents need to be located at a minimum of one foot above ground level, be turned down and be covered with a non-corrodible screen. Screens may not have openings that exceed 0.07 inches (typically 12 or 16 mesh screen).
The two most common issues observed with vents on wells are that they are broken or missing.
The well-cap has a built-in vent that was broken/corroded. The supplier replaced the broken screen with an acceptable mesh screen.
Electrical Conduit
According to the Colorado Well Driller Regulation, electrical connections are to meet the standards of the NFPA 70: National Electric Code (2014). Some common electrical conduit issues that are observed during sanitary surveys are where the electrical conduit has separated from the well head or the junction box which can typically occur due to the ground settling. Another common finding is missing or partially attached cover plates on electrical junction boxes. Split-cap wells can also have electrical wires penetrating the well top without a properly constructed conduit or a proper seal between the wire and the rubber gasket. All of these situations present a pathway for contaminants to enter the well, which pose a health risk and are significant deficiencies that will be cited during a sanitary survey.
The electrical conduit separated from the electrical junction box, creating an opening. The supplier installed a conduit sleeve to provide a watertight junction.
The electrical junction box was missing a screw. The supplier sealed the hole with caulk.
Split-cap well had the electrical wire enter from an unsealed port. The supplier sealed the gap with caulk.
Well Vaults
Although well vaults are not a common practice these days, the department still observes wells located in vaults. Placing a well in a vault was a common practice to protect the well from the elements. However, having a well in a vault can subject the well to flooding. If a well is located in a vault, the vault cover or lid must be watertight and the vault must either drain to daylight or have a sump. Evidence of water accumulating in the vault and potentially submerging the wellhead is a significant deficiency.
Well vault was subject to flooding. Supplier installed a sump pump.
Concrete Pads
Inspectors are frequently asked if concrete pads are required? The Colorado Well Driller Regulation along with the department do not recommend that wells have concrete pads with the exception of hand-pumped wells. Well pads were commonly installed if well depths were less than 100 feet or to keep vegetation down around the well head. However, the department has observed that concrete pads tend to attract animals that burrow underneath the pad creating a source of contamination. Concrete pads also tend to crack and shift, which can create a funnel effect and divert surface water to the well casing. Minor cracks can be repaired; however, the department recommends that a supplier remove their existing concrete pad if they notice animals burrowing or if the concrete pad begins to divert surface water to the well casing. Evidence of burrows under a concrete pad or severely damaged pads capable of channeling surface water to the well casing are significant deficiencies that would be cited during a sanitary survey.
Burrow located under the concrete pad, the burrow was filled in and will be monitored in the future.
Drainage and Slope
According to the Colorado Well Driller Regulation, well locations should incorporate proper positive drainage from the well casing. As a rule of thumb, the department has historically viewed positive drainage 20 feet in all directions from the well if possible. Wells should not be located in depressions as surface water can pool around the well casing and be a source of contamination. If a well is built on a slope, a berm is recommended uphill to divert runoff and surface water away from the well casing.
Well was located in a depression that could allow for water to pool around the well casing. The supplier added pea gravel around the well head and created positive drainage away from the well casing.
For more information the department recommends that suppliers utilize DNR’s latest edition of “2 CCR 402-2 Rules and Regulations for Water Well Construction, Pump Installation, Cistern Installation, and Monitoring and Observation Hole/Well Construction” for proper well construction, maintenances and fixes. In addition, suppliers may email the Field Services team at cdphe_wqcd_fss_questions@state.co.us if they have any questions or concerns.
➽ Tom Valenta, CWP, Field Services Work Group Leader
