<small>Simplified cross section of a standard monitoring well.</small><ref> Hawaii State Department of Health. (n.d.). TGM for the Implementation of the Hawai'i State Contingency Plan. Subsection 6.2. MONITORING WELL INSTALLATION AND ABANDONMENT. Retrieved August 27, 2021, from http://hawaiidoh.org/tgm-content/0602a.aspx?f=T </ref>
<small>Simplified cross section of a standard monitoring well.</small><ref> Hawaii State Department of Health. TGM for the Implementation of the Hawai'i State Contingency Plan. Subsection 6.2. MONITORING WELL INSTALLATION AND ABANDONMENT. http://hawaiidoh.org/tgm-content/0602a.aspx?f=T. Published (n.d.). Retrieved August 27, 2021. </ref>