Minnesota Administrative Rules
Agency 144 - Health Department
Chapter 4725 - WELLS AND BORINGS
MONITORING WELLS
Part 4725.6650 - CONSTRUCTION OF MONITORING WELLS
Current through Register Vol. 49, No. 13, September 23, 2024
Subpart 1. Casing.
Casing for a monitoring well must be steel or plastic casing meeting the standards of parts 4725.2250 to 4725.2650, or stainless steel or flush threaded polyvinyl chloride meeting the standards of this subpart.
Subp. 2. Grouting of annular space.
The annular space of a monitoring well must be grouted from ten feet or less above the screen or open bore hole to the established ground surface according to part 4725.3050, except that no cuttings from the bore hole must be added to the grout. Neat-cement or cement-sand grout may terminate at the base of the manhole or vault for an at-grade installation.
Subp. 3. Exception to drilling fluids.
Drilling fluids used to construct a monitoring well must comply with part 4725.2950, except that a free chlorine residual is not required.
Subp. 4. Screen or open hole across an unconsolidated formation and bedrock contact.
A monitoring well, that is constructed to monitor contaminants at the water surface, by placing a screen or open hole across the contact of an unconsolidated formation and bedrock according to part 4725.6050, subpart 3, is exempt from part 4725.2020, subpart 1.
Statutory Authority: MS s 103I.101; 103I.111; 103I.205; 103I.221; 103I.301; 103I.401; 103I.451; 103I.501; 103I.525; 103I.531; 103I.535; 103I.541; 103I.621; 144.05; 144.12; 144.122; 144.383; 157.04; 157.08; 157.09; 157.13