Rule 3745-65-92 | Sampling and analysis - groundwater monitoring.
(A) The owner or operator shall obtain and analyze samples from the installed groundwater monitoring system. The owner or operator shall develop and follow a groundwater sampling and analysis plan. The owner or operator shall keep this plan at the facility. The plan shall include procedures and techniques for:
(1) Sample collection;
(2) Sample preservation and shipment;
(3) Analytical procedures; and
(4) Chain of custody control.
[Comment: See Ohio EPA's "Technical Guidance Manual (TGM) for Hydrogeologic Investigations and Ground Water Monitoring" for discussions of sampling and analysis procedures. See rule 3745-50-11 of the Administrative Code titled "Incorporated by reference" for information on accessing this document.]
(B) The owner or operator shall determine the concentration or value of the following parameters in groundwater samples in accordance with paragraphs (C) and (D) of this rule:
(1) Parameters characterizing the suitability of the groundwater as a drinking water supply, as specified in the table in this rule.
(2) Parameters establishing groundwater quality:
(a) Chloride.
(b) Iron.
(c) Manganese.
(d) Phenols.
(e) Sodium.
(f) Sulfate.
[Comment: These parameters are to be used as a basis for comparison in the event a groundwater quality assessment is required under paragraph (D) of rule 3745-65-93 of the Administrative Code.]
(3) Parameters used as indicators of groundwater contamination:
(a) pH.
(b) Specific conductance.
(c) Total organic carbon.
(d) Total organic halogen.
(C)
(1) For all monitoring wells, the owner or operator shall establish initial background concentrations or values of all parameters specified in paragraph (B) of this rule. The owner or operator shall do this quarterly for one year.
(2) For each of the indicator parameters specified in paragraph (B)(3) of this rule, at least four replicate measurements shall be obtained for each sample, and the initial background arithmetic mean and variance shall be determined by pooling the replicate measurements for the respective parameter concentrations or values in samples obtained from upgradient wells during the first year.
(D) After the first year, all monitoring wells shall be sampled and the samples analyzed with the following frequencies:
(1) Samples collected to establish groundwater quality shall be obtained and analyzed for the parameters specified in paragraph (B)(2) of this rule at least annually.
(2) Samples collected to indicate groundwater contamination shall be obtained and analyzed for the parameters specified in paragraph (B)(3) of this rule at least semi-annually.
(E) Elevation of the groundwater surface at each monitoring well shall be determined each time a sample is obtained.
| Parameter | Maximum Level milligrams per liter (mg/L) |
| Arsenic | 0.01 |
| Barium | 2.0 |
| Cadmium | 0.005 |
| Chromium | 0.1 |
| Fluoride | 4.0 |
| Lead | 0.015 |
| Mercury | 0.002 |
| Nitrate (as N) | 10.0 |
| Selenium | 0.05 |
| Silver | 0.01 |
| Endrin | 0.002 |
| Lindane | 0.0002 |
| Methoxychlor | 0.04 |
| Toxaphene | 0.003 |
| 2,4-D | 0.07 |
| 2,4,5-TP (Silvex) | 0.05 |
| Radium | 5 picoCuries per liter (pCi/L) |
| Gross Alpha | 15 pCi/L |
| Gross Beta | 4 pCi/L |
| Turbidity | 5 nephelometric turbidity units (NTU) |
| Coliform Bacteria | no fecal at all; 5 per cent of all other |
[Comment: For dates of non-regulatory government publications, publications of recognized organizations and associations, federal rules, and federal statutory provisions referenced in this rule, see rule 3745-50-11 of the Administrative Code titled "Incorporated by reference."]
Last updated January 16, 2026 at 4:18 AM
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