Part 22 Rule 2222 Standards

Rule 2222 of the Part 22 Rules defines Standards for groundwater discharge quality used in the Groundwater Discharge Program.

There are specific circumstances where permit limits may differ from the defined standards. Review all Part 22 Rules for full details. When applicable, Standards are derived from groundwater cleanup criteria for residential drinking water. If a discharge to groundwater vents to surface water, contact an EGLE Groundwater Discharge Program geologist for applicable standards.

Below the table there is an explanation of how the Standards are calculated, column descriptions, and a list of footnotes.

Rule 2222 Standards Table

Download the table as an .xlsx file.

How Standards are Calculated

Some Standard definitions reference Part 201, Environmental Remediation, of Michigan's Natural Resources and Environmental Protection Act, 1994 PA 451, as amended (Part 201). Part 201 includes groundwater cleanup criteria requirements in R 299.44 of the administrative code for Part 201. One set of criteria is applicable for residential drinking water. Another set of criteria is applicable for groundwater venting to surface water, also called groundwater surface water interface. The Standards Table only includes Standards derived from groundwater cleanup criteria applicable for residential drinking water because that is most common in the Groundwater Discharge Program. If a discharge to groundwater vents to surface water, contact an EGLE Groundwater Discharge Program geologist for applicable standards.

Standards are grouped by subsections of Rule 2222 that use the same calculation:

• 2a and 2b: The Standard is the lessor of the concentration defined in Rule 2222 or the concentration at which a Part 201 facility is created.
• 3a, 3b, 3c, 3d, 3e, and 3f: The Standard is the lessor of the concentration defined in Rule 2222 or the concentration at which a Part 201 facility is created.
• 4a, 4b, 4c, and 4d: The Standard is 20% of the concentration of total trihalomethanes at which a Part 201 facility is created. See Footnote T, below.
• 5a: The Standard is half of the concentration at which a Part 201 facility is created. This assumes that the background concentration is 0. Site-specific background concentrations may affect an individual permit.
• 5b: The Standard is the lessor of the concentration defined in Rule 2222 or the concentration at which a Part 201 facility is created. If the concentration of the substance in the effluent exceeds the Standard, then the discharger shall take initial response as required by Rule 2228 of the Part 22 Rules.
• 5c: The Standard is the concentration at which a Part 201 facility is created. If the substance is detected in groundwater, then the discharger shall take initial response as required by Rule 2228 of the Part 22 Rules.
• 5d: The Standard is the concentration at which a Part 201 facility is created.
• 7h: The Standard is defined individually for each chemical under this subsection, based on unique chemical properties.

Column Descriptions

• Chemical Name: An identifying name for each substance. Some substances may have other names not listed here.
• CAS Number: The Chemical Abstracts Service (CAS) Number is a unique identification number for each substance based off the CAS Registry^®.
• Standard (ug/l): The Standard presented in micrograms per liter (ug/l); 1 ug/l is equivalent to 1 part per billion (ppb). 1 ug/l is equivalent to 0.001 milligrams per liter (mg/l).
• Footnote: Notes for specific substances are provided in the footnotes below the table.
• Monitoring Point: The monitoring point refers to the location where the substance must be monitored for compliance with the Standard. The monitoring point may be Effluent, Groundwater, Either, or Both. Effluent means waste or wastewater during or subsequent to treatment but before discharge. Groundwater monitoring is defined in Rule 2224 of the Part 22 Rules.
• Rule 2222 Subsection: The Standard for each substance is regulated as defined under a particular subsection of Rule 2222, presented by the first order (numeric) and second order (alphabetic) subsection identifiers in Rule 2222.

Footnotes for the Standards Table

• A: The Standard for asbestos is 3.5 million fibers per liter. Asbestos is regulated by Rule 2222(5)(a), so the Standard is half of the concentration at which a Part 201 facility is created. The concentration at which a Part 201 facility is created for asbestos is 7.0 million fibers (fibers greater than 10 micrometers in length) per liter.
• H: See Footnote H in the Part 201 Footnotes of the Cleanup Criteria Requirements for Response Activity.
• J: See Footnote J in the Part 201 Footnotes of the Cleanup Criteria Requirements for Response Activity.
• M: The Standard is less than the detection value; see Rule 2222(5)(e) of the Part 22 Rules for more details.
• N: The Standard for total inorganic nitrogen (TIN) is 5,000 ug/l. TIN equals the sum of ammonia, nitrate, and nitrite. Additionally, nitrite alone cannot exceed 500 ug/l.
• O: See Footnote O in the Part 201 Footnotes of the Cleanup Criteria Requirements for Response Activity.
• P: The Standard listed for phosphorous of 1,000 ug/l measured in effluent is for discharges with a body of surface water within 1,000 feet hydraulically downgradient of the discharge. For other discharges, the Standard is 5,000 ug/l measured in effluent.
• R: There is insufficient data to develop the concentration at which a Part 201 facility is created. Contact an EGLE Groundwater Discharge Program geologist for applicable standards.
• S: See Footnote S in the Part 201 Footnotes of the Cleanup Criteria Requirements for Response Activity.
• T: The Standard for total trihalomethanes (THM) is 16 ug/l. Total THM equals the sum of the concentrations of chloroform, bromodichloromethane, dibromochloromethane, and bromoform. The Standard is 20% of the concentration of THM at which a Part 201 facility is created. The concentration of THM at which a Part 201 facility is created is 80 ug/l.
• U: The Standard for chloride is set in Section 324.3109e of Part 31 of NREPA. The limitation for chloride in groundwater may not be more restrictive than 250 milligrams of chloride per liter. The limitation for chloride in effluent may not be more restrictive than 500 milligrams of chloride per liter. This statute supersedes the Standard prescribed in Rule 2222(3)(b). For consistency, the Standard is presented in ug/l, while the Part 31 statute uses units of mg/l.
• V: The Standard for sodium is set in Section 324.3109e of Part 31 of NREPA. The limitation for sodium in groundwater may not be more restrictive than 230 milligrams of sodium per liter. The limitation for sodium in effluent may not be more restrictive than 400 milligrams of sodium per liter. This statute supersedes the Standard prescribed in Rule 2222(3)(c). For consistency, the Standard is presented in ug/l, while the Part 31 statute uses units of mg/l.
• Z: See Footnote Z in the Part 201 Footnotes of the Cleanup Criteria Requirements for Response Activity.
• BOD: The Standard for biological oxygen demand (BOD) is 50 lbs/acre/day for land treatment and 30 milligrams per liter (mg/l) for rapid infiltration.
• DO: Dissolved oxygen (DO) may not be less than 7,000 ug/l for cold receiving waters or 5,000 ug/l for warm receiving waters. Contact an EGLE Groundwater Discharge Program geologist for a definition of cold and warm receiving waters. The DO Standard does not apply if groundwater carbonaceous biochemical oxygen demand (CBOD) is less than 10,000 ug/l and the groundwater ammonia concentration is less than 2,000 ug/l.
• pH: The Standard for pH in effluent and groundwater ranges between 6.5-8.5 standard units (SU). The Standard for pH that is protective of surface water ranges between 6.5-9.0 SU.
• TDS: If total dissolved solids (TDS) data are not available, TDS may be based on the sum of the following concentrations: calcium, chloride, iron, magnesium, potassium, sodium, and sulfate.