1.4 Federal & State Drinking Water & Clean Water Acts
Key Takeaways
- The Safe Drinking Water Act sets enforceable primary drinking-water requirements and non-enforceable federal secondary aesthetic guidelines.
- The Clean Water Act establishes NPDES; Missouri administers its authorized discharge-permit program through Missouri State Operating Permits under RSMo Chapter 644.
- Missouri has EPA-approved primary enforcement responsibility for the SDWA public-water program and separate authorization to administer NPDES; state requirements must satisfy the applicable federal program criteria and may be more protective.
- DMR and operating-report schedules come from the MSOP, drinking-water rule or approved form; Missouri eDMRs commonly use the 28th of the following month, but operators must read the facility-specific requirement.
- MSOP conditions commonly require 24-hour oral and 5-day written reporting for qualifying noncompliance that may endanger health or the environment. Drinking-water Tier 1 notice, low-pressure reporting and emergency-release calls follow separate triggers and deadlines.
Water and wastewater operations in Missouri exist within a comprehensive system of federal statutes, state laws, operating permits, and mandatory reporting protocols. Every certified operator must understand the legal authority governing their facility to ensure continuous compliance and protect downstream communities.
Federal Statutory Foundations: SDWA & CWA
Two landmark federal statutes form the foundation of United States water law:
1. Safe Drinking Water Act (SDWA) of 1974
Enacted to protect public health by regulating the nation's public drinking water supply. Key historical amendments include:
- 1986 Amendments: Mandated rapid establishment of Maximum Contaminant Levels (MCLs) for 83 specific contaminants, required filtration for surface water supplies under the Surface Water Treatment Rule (SWTR), banned lead pipes and lead flux/solder in public plumbing, and significantly increased EPA enforcement authority.
- 1996 Amendments: Emphasized source water protection, required annual Consumer Confidence Reports (CCRs) delivered to all water consumers by July 1, established the Drinking Water State Revolving Fund (DWSRF) for infrastructure financing, and mandated operator certification programs for all community and non-transient non-community water systems.
2. Clean Water Act (CWA) of 1972
Originally enacted as the Federal Water Pollution Control Act Amendments of 1972, the Clean Water Act established the national objective to restore and maintain the chemical, physical, and biological integrity of the nation's waters.
- NPDES Permitting: Created the National Pollutant Discharge Elimination System (NPDES) under Section 402, making it unlawful to discharge any pollutant from a point source into navigable waters without an active NPDES permit.
- Secondary Treatment Standards: Established baseline technology-based standards for Publicly Owned Treatment Works (POTWs), mandating minimum 30-day average effluent limits of 30 mg/L for 5-day Biochemical Oxygen Demand (BOD5), 30 mg/L for Total Suspended Solids (TSS), 85% removal efficiency for BOD5 and TSS, and an effluent pH range of 6.0 to 9.0.
Primary vs. Secondary Drinking Water Standards
The SDWA establishes two distinct categories of drinking water standards:
| Standard Category | Regulatory Status | Purpose & Health Basis | Examples & Regulatory Limits |
|---|---|---|---|
| National Primary Drinking Water Regulations (NPDWRs) | Legally Enforceable | Protects public health against biological, chemical, radiological, and physical contaminants. | Nitrate: 10 mg/L (as N)<br/>Nitrite: 1.0 mg/L (as N)<br/>Total Coliform / E. coli: Zero / Treatment Technique<br/>Lead Action Level: 0.015 mg/L (15 ug/L)<br/>Copper Action Level: 1.3 mg/L<br/>Turbidity: <= 0.3 NTU in 95% of monthly samples (surface water). |
| National Secondary Drinking Water Regulations (NSDWRs) | Non-Enforceable Federal Guidelines (Adopted as enforceable by some states) | Controls aesthetic qualities including taste, odor, color, foaming, staining, and corrosiveness. | Iron: 0.3 mg/L (causes red/brown staining)<br/>Manganese: 0.05 mg/L (causes black staining/taste)<br/>Total Dissolved Solids (TDS): 500 mg/L<br/>Chloride: 250 mg/L<br/>Sulfate: 250 mg/L<br/>pH Range: 6.5 to 8.5 s.u. |
- Maximum Contaminant Level Goal (MCLG): The non-enforceable level of a contaminant in drinking water below which there is no known or expected risk to health (e.g., MCLG for lead and Giardia is zero). Primary MCLs are set as close to MCLGs as feasible using the best available treatment technology and economic considerations.
Missouri Statutory Framework & State Primacy Delegation
US EPA Region 7, headquartered in Lenexa, Kansas, oversees federal programs in Missouri, Kansas, Iowa and Nebraska. Missouri has primary enforcement responsibility for its SDWA public-water program and separate EPA authorization to administer the NPDES discharge-permit program.
+-----------------------------------------------------------------------------------------+
| STATE PRIMACY ARCHITECTURE |
+-----------------------------------------------------------------------------------------+
| US EPA Region 7 (Federal SDWA & CWA Oversight) |
| | |
| v (Primacy Delegation: State rules >= Federal standards) |
| Missouri Department of Natural Resources (MoDNR) |
| | |
| +---> RSMo Chapter 640 -> 10 CSR 60 (Missouri Safe Drinking Water Regulations) |
| +---> RSMo Chapter 644 -> 10 CSR 20 (Missouri Clean Water Regulations & MSOPs) |
+-----------------------------------------------+-----------------------------------------+
- Program-authorization principle: Missouri must continue to meet the federal approval criteria for each delegated or authorized program. It may adopt additional or more protective state requirements. SDWA primacy and NPDES authorization are related federal-state arrangements, but they are not the same legal delegation.
- State Statutes:
- RSMo Chapter 640 (Missouri Safe Drinking Water Law) authorizes state drinking water oversight, construction permits, and operator licensing under the Safe Drinking Water Commission.
- RSMo Chapter 644 (Missouri Clean Water Law) authorizes the Clean Water Commission to issue discharge permits, establish stream water quality standards, and enforce anti-pollution mandates.
Missouri State Operating Permits (MSOP)
In Missouri, NPDES permits are issued by MoDNR under the title of Missouri State Operating Permits (MSOP) pursuant to 10 CSR 20-6. Every point source discharge—including municipal wastewater plants, industrial treatment systems, and concentrated animal feeding operations—must maintain an active MSOP.
- Permit Limits: An MSOP establishes numerical discharge limits for parameters such as CBOD5/BOD5, TSS, Escherichia coli (E. coli), Ammonia as N (NH3-N), Dissolved Oxygen (DO), pH, Total Nitrogen, Total Phosphorus, and specific industrial toxic compounds.
- Permit Term: Operating permits are normally issued for a fixed term of 5 years. Permittees must submit a formal permit renewal application at least 180 days prior to the expiration date to ensure continuous permit coverage.
Compliance Reporting: DMRs and MORs
Permitted facilities must routinely document compliance and transmit analytical data to MoDNR through structured periodic reports:
| Report Type | Facility Type | Submission Mechanism | Frequency & Due Date | Key Contents & Parameters |
|---|---|---|---|---|
| Discharge Monitoring Report (DMR) | MSOP permittees with monitoring requirements | Electronic submission through the required MoDNR system | Frequency and deadline stated in the permit; many Missouri eDMRs are due by the 28th of the following month | The permit’s concentration, loading, flow and other monitoring results |
| Drinking-water operating report / records | Public water systems for which a rule, permit-to-dispense condition or department form requires it | Required form or electronic method | Use the deadline on the governing rule, approval or form; do not assume one universal 10th/15th deadline | Pumpage, treatment performance, disinfectant, turbidity, chemical feed and operational records as applicable |
Emergency Non-Compliance & Spill Notification Protocols
Reporting depends on the program, permit and event. The MSOP 24-hour/5-day pathway below applies to qualifying wastewater noncompliance; drinking-water and spill requirements use separate triggers.
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| TWO-STAGE EMERGENCY NOTIFICATION PROTOCOL |
+-----------------------------------------------------------------------------------------+
| Stage 1: IMMEDIATE VERBAL NOTIFICATION (Within 24 Hours) |
| Notify the contact specified by the MSOP for qualifying noncompliance that may |
| endanger health or the environment, including a major bypass or SSO.
| |
| Stage 2: FORMAL WRITTEN REPORT (Within 5 Calendar Days) |
| Submit comprehensive technical report detailing cause, volume, duration, |
| environmental impact, corrective actions, and long-term prevention plan. |
+-----------------------------------------------------------------------------------------+
The 24-Hour Verbal Notification Rule
Read the actual MSOP. Standard conditions require oral reporting within 24 hours for listed noncompliance that may endanger health or the environment, such as a significant unanticipated bypass or major SSO. Other permit conditions may require faster notice.
Do not automatically apply the MSOP timeline to drinking water. A Tier 1 drinking-water violation generally requires consultation with the department and public notice within 24 hours; a Missouri distribution pressure drop below 20 psi is reported to the department under the current low-pressure procedure within 48 hours. Hazardous releases may require an immediate call to MoDNR Environmental Emergency Response at 573-634-2436 and other agencies based on the material and quantity.
The 5-Day Written Incident Report
Within 5 calendar days following the 24-hour verbal notice, the facility must submit a formal written incident report to the MoDNR Regional Office containing:
- Exact description and location of the discharge or non-compliance event.
- Estimated total volume spilled or discharged and precise duration (start and stop times).
- Root cause analysis (e.g., mechanical pump failure, power outage, severe inflow/infiltration from storm event, grease blockage).
- Environmental impact assessment on the receiving stream or drinking water supply.
- Immediate containment, recovery, disinfection or public-protection steps appropriate to the event and approved response plan.
- Detailed corrective engineering and operational measures implemented to prevent recurrence.
Which of the following drinking water quality parameters is classified as a National Secondary Drinking Water Regulation (NSDWR) focusing on aesthetic qualities rather than direct acute health toxicity?
For Missouri’s EPA-approved SDWA primacy program, what is the general relationship between state drinking-water requirements and federal requirements?
A municipal lift station experiences a catastrophic mechanical power failure, resulting in an unpermitted Sanitary Sewer Overflow (SSO) of 50,000 gallons of raw sewage into a local creek. What are the mandatory reporting timelines required by MoDNR?