2.1 Federal & State Drinking Water Regulations

2.1 Federal & State Drinking Water Regulations

Core Principle: Clean drinking water protection in New Jersey relies on a dual regulatory framework: the federal Safe Drinking Water Act (SDWA) setting baseline national standards, and the New Jersey Safe Drinking Water Act (N.J.S.A. 58:12A / N.J.A.C. 7:10) administered by the New Jersey Department of Environmental Protection (NJDEP). New Jersey maintains primary enforcement responsibility (primacy) and routinely enacts state standards that are more stringent than federal baselines.

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1. Statutory Architecture: SDWA & N.J.A.C. 7:10

The Safe Drinking Water Act (SDWA), originally enacted by Congress in 1974 and substantively amended in 1986 and 1996, authorizes the U.S. Environmental Protection Agency (EPA) to set national health-based standards for drinking water to protect against both naturally occurring and human-made contaminants. Under 40 CFR Parts 141, 142, and 143, the EPA establishes National Primary Drinking Water Regulations (NPDWRs) and National Secondary Drinking Water Regulations (NSDWRs).

In New Jersey, the state legislature passed the New Jersey Safe Drinking Water Act (N.J.S.A. 58:12A-1 et seq.), implemented through administrative regulations at N.J.A.C. 7:10. The NJDEP Division of Water Supply & Geoscience directly enforces these regulations. New Jersey operators must understand that where state and federal standards diverge, the more stringent standard always governs.

Public Water System (PWS) Classifications

A Public Water System (PWS) is defined under both federal and New Jersey law as any publicly or privately owned system that provides water for human consumption through pipes or other constructed conveyances, if such system has at least 15 service connections or regularly serves an average of at least 25 individuals daily at least 60 days out of the year. PWSs are categorized into three distinct operating classes:

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2. Regulatory Limits: MCLGs, MCLs, and Treatment Techniques

The SDWA regulatory framework establishes three primary regulatory metrics that licensed operators must navigate:

Maximum Contaminant Level Goal (MCLG)

• Definition: The maximum level of a contaminant in drinking water at which no known or anticipated adverse effect on human health would occur, allowing an adequate margin of safety.
• Legal Status: Non-enforceable health goals developed strictly through toxicological and epidemiological risk assessments.
• Guiding Rule: For known or probable human carcinogens (e.g., benzene, vinyl chloride, arsenic) and microbiological pathogens (Giardia, Cryptosporidium, viruses, Legionella, E. coli), the EPA sets the MCLG strictly at zero (0).

Maximum Contaminant Level (MCL)

• Definition: The highest permissible concentration of a contaminant delivered to any user of a public water system.
• Legal Status: Legally enforceable standard. Under the SDWA, the EPA and NJDEP must set the MCL as close to the MCLG as is technologically and economically feasible, using the Best Available Technology (BAT), affordable treatment techniques, and certified analytical laboratory detection limits (Practical Quantitation Levels, or PQLs).

Treatment Technique (TT)

• Definition: An enforceable operational procedure or treatment performance requirement that a public water system must follow to control the level of a contaminant.
• Application: Established in lieu of an MCL when it is economically or technologically infeasible for laboratories to ascertain the exact concentration of a contaminant in water (e.g., measuring live Giardia cysts or calculating lead leaching inside private household plumbing).

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3. Primary vs. Secondary Drinking Water Standards

Drinking water standards are bifurcated into health-based requirements and aesthetic guidelines:

National Primary Drinking Water Regulations (NPDWRs)

• Enforceable health standards (MCLs or Treatment Techniques).
• Mandate routine water quality testing, strict analytical methodologies, record retention, and statutory public notification schedules.
• Cover volatile organic compounds (VOCs), synthetic organic compounds (SOCs), inorganic contaminants (IOCs), radiological contaminants, disinfection byproducts, and microbial pathogens.

National Secondary Drinking Water Regulations (NSDWRs)

• Non-enforceable federal guidelines established under 40 CFR Part 143 to control aesthetic parameters such as taste, odor, color, foaming, and plumbing corrosion.
• In New Jersey, N.J.A.C. 7:10-7 establishes state Secondary Maximum Contaminant Levels (SMCLs). While SMCLs do not carry automatic federal Tier 1 or Tier 2 public notices, the NJDEP can mandate corrective treatment or operational adjustments if aesthetic violations trigger severe consumer complaints or cause structural pipe degradation.

| Contaminant / Parameter | Secondary Standard (SMCL) | Aesthetic & Operational Impact | |---|---|---|| | Iron (Fe) | 0.3 mg/L (300 µg/L) | Reddish-brown staining of laundry and porcelain fixtures; metallic taste; promotes iron bacteria growth (Gallionella) and pipe tuberculation. | | Manganese (Mn) | 0.05 mg/L (50 µg/L) | Dark brown or black staining; bitter metallic taste; precipitate accumulation in storage tanks and distribution dead ends. | | Total Dissolved Solids (TDS) | 500 mg/L | Mineral deposits, scaling on heat exchangers, salty or brackish taste, increased electrical conductivity. | | pH | 6.5 – 8.5 S.U. | Low pH (<6.5) accelerates pipe corrosion and metal leaching; high pH (>8.5) causes scale formation and reduces chlorine disinfection efficiency. | | Odor | 3 Threshold Odor Number (TON) | Earthy, musty, or swampy odors often caused by algae metabolites (geosmin, MIB). | | Color | 15 Color Units (CU) | Aesthetic discoloration; tea-like tint from natural organic matter (humic and fulvic acids). | | Aluminum | 0.05 – 0.2 mg/L | Post-treatment floc precipitation in distribution mains; turbidity haze. | | Chloride | 250 mg/L | Salty taste; significantly increases the Chloride-to-Sulfate Mass Ratio (CSMR), accelerating galvanic corrosion of lead solder. | | Sulfate | 250 mg/L | Laxative effect on unaccustomed consumers; bitter medicinal taste. | | Copper (Aesthetic) | 1.0 mg/L | Blue-green staining on plumbing fixtures and porcelain; bitter metallic taste. (Note: Distinguish from the health-based Action Level of 1.3 mg/L). | | Zinc | 5.0 mg/L | Metallic taste; milky appearance in water. |

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4. Major National Primary Drinking Water Regulations

Surface Water Treatment Rule (SWTR) & Pathogen Control

The Surface Water Treatment Rule (SWTR) and its subsequent iterations—the Interim Enhanced SWTR (IESWTR), Long Term 1 (LT1ESWTR), and Long Term 2 (LT2ESWTR)—apply to all public water systems using surface water or Groundwater Under the Direct Influence of surface water (GWUDI). The rule establishes a multi-barrier framework requiring coagulation, flocculation, sedimentation, filtration, and disinfection.

Mandatory Pathogen Log-Removal & Inactivation

The complete treatment process train must achieve verified minimum cumulative log reductions:

• Giardia lamblia cysts: Minimum 3-log (99.9%) removal and/or inactivation.
• Enteric viruses: Minimum 4-log (99.99%) removal and/or inactivation.
• Cryptosporidium oocysts: Minimum 2-log (99.0%) removal under conventional filtration, with additional log-credit requirements assigned under LT2ESWTR based on raw water source monitoring Bins (Bins 1 through 4).

$\text{Log Reduction} = \log_{10}\left(\frac{C_{\text{in}}}{C_{\text{out}}}\right)$

• $1\text{-log reduction} = 90%$ reduction
• $2\text{-log reduction} = 99%$ reduction
• $3\text{-log reduction} = 99.9%$ reduction
• $4\text{-log reduction} = 99.99%$ reduction

Turbidity Compliance Limits

Turbidity is regulated as a critical operational surrogate for microbiological safety, as suspended colloidal particles shield pathogens from chemical disinfectants:

• Combined Filter Effluent (CFE): For conventional and direct granular media filtration plants, CFE turbidity must be $\le$ 0.3 NTU (Nephelometric Turbidity Units) in at least 95% of the measurements taken each calendar month.
• Maximum Instantaneous Turbidity: CFE turbidity must never exceed 1.0 NTU at any time. Any single reading exceeding 1.0 NTU is an immediate Treatment Technique violation.
• Individual Filter Effluent (IFE): Continuous online turbidimeters must monitor each individual filter run. If an IFE exceeds 0.5 NTU after the first 4 hours of operation, exceeds 1.0 NTU in two consecutive 15-minute readings, or exceeds 2.0 NTU in two consecutive 15-minute readings in two consecutive months, the utility must execute filter self-assessments, profiling, or comprehensive performance evaluations (CPE).

Finished Water Disinfectant Residual Standards

• Point of Entry (POE): Disinfectant residual entering the distribution system cannot be less than 0.2 mg/L (free or combined chlorine) for more than 4 consecutive hours.
• Distribution Network: A detectable disinfectant residual must be maintained throughout the distribution system in at least 95% of samples analyzed each month. An undetectable residual is deemed acceptable only if the Heterotrophic Plate Count (HPC) is $\le$ 500 CFU/mL.

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5. The Ground Water Rule (GWR)

New Jersey has far more groundwater systems than surface water systems, so the Ground Water Rule (GWR, 40 CFR 141 Subpart S) governs the majority of the state's public water systems. It applies to all public water systems that use ground water, including consecutive systems that purchase groundwater, and its purpose is to reduce the risk of illness from fecal contamination of a groundwater source.

The GWR uses a targeted, risk-based strategy rather than a universal treatment technique:

Exam Trap Alert: The GWR benchmark is 4-log (99.99 percent) inactivation or removal of viruses, not the 3-log Giardia / 4-log virus pairing of the Surface Water Treatment Rule. A groundwater system that documents 4-log virus treatment at each well is exempt from triggered source water monitoring, which is the main operational incentive to install and document it.

Fecal indicators used under the GWR are E. coli, enterococci, and coliphage. A confirmed fecal indicator-positive source sample requires the system to notify the State and issue Tier 1 public notification within 24 hours.

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6. Disinfection Byproducts Rules (Stage 1 & Stage 2 DBPR)

Chemical disinfection creates unintended byproducts when free chlorine reacts with naturally occurring organic matter (NOM) measured as Total Organic Carbon (TOC) and bromide in source water.

Regulated Disinfection Byproducts & Disinfectant Residuals

Stage 1 RAA vs. Stage 2 LRAA Compliance Calculation

A pivotal exam concept is the mathematical shift in compliance calculations between Stage 1 and Stage 2 DBPR:

• Stage 1 DBPR (Historical): Compliance was determined using a system-wide Running Annual Average (RAA). All sample results from across the entire distribution system were averaged together over 4 quarters. This allowed utilities to average high-concentration samples from stagnant dead ends with low-concentration samples near the treatment plant, masking localized public health hazards.
• Stage 2 DBPR (Current Standard): Compliance is determined strictly using a Locational Running Annual Average (LRAA). The rolling four-quarter average is calculated independently at each specific sampling location:

$\text{LRAA}_{\text{Site } X} = \frac{Q_1 + Q_2 + Q_3 + Q_4}{4}$

If the LRAA at any single monitoring station exceeds 80 ppb for TTHM or 60 ppb for HAA5, the entire water system is in violation of the MCL.

Operational Evaluation Level (OEL)

To prevent compliance excursions before they occur, Stage 2 DBPR establishes the Operational Evaluation Level (OEL). The OEL projects whether the upcoming quarter's result will cause an LRAA exceedance:

$\text{OEL} = \frac{Q_{\text{previous 2}} + Q_{\text{previous 1}} + (2 \times Q_{\text{current}})}{4}$

If the calculated OEL exceeds 80 ppb for TTHM or 60 ppb for HAA5 at any site, the water utility must conduct an Operational Evaluation of treatment and distribution practices and submit a detailed technical report to the NJDEP within 90 days.

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7. Lead and Copper Rule (LCR) & Improvements (LCRI)

Lead and copper enter drinking water almost exclusively through the corrosion of interior plumbing pipes, lead solder, brass fixtures, and lead service lines (LSLs). Because these contaminants originate inside customer-owned plumbing, they are regulated through a Treatment Technique using Action Levels (AL) rather than finished water plant MCLs.

Action Levels & The 90th Percentile Rule

• Lead Action Level: 0.015 mg/L (15 µg/L or 15 ppb). (Note: The federal Lead and Copper Rule Improvements [LCRI] lower the regulatory action level framework to 10 ppb, while New Jersey enforces aggressive state lead containment mandates).
• Copper Action Level: 1.3 mg/L (1,300 µg/L or 1,300 ppb).

Compliance is evaluated based on the 90th percentile of all valid first-draw compliance samples collected during the monitoring period (typically 6-month or annual cycles):

1. Arrange all analytical results in ascending order from lowest concentration to highest concentration.
2. Assign an integer rank to each sample starting from 1 up to $N$ (total number of samples).
3. Calculate the 90th percentile index: $\text{Index} = N \times 0.90$.
4. If $N = 30$ samples, the 90th percentile value is the concentration of the 27th sample ($30 \times 0.90 = 27$). If $N = 50$ samples, it is the 45th sample ($50 \times 0.90 = 45$).
5. If the concentration at the 90th percentile rank exceeds the Action Level, the system incurs an Action Level Exceedance (ALE).

First-Draw Sampling Protocol

Samples must be collected strictly according to federal and NJDEP guidelines:

• Sampling Tap: Un-aerated cold water tap in a high-risk residence (Tier 1 sites: single-family residences with lead service lines, lead interior piping, or copper pipes with lead solder installed between 1982 and 1988).
• Stagnation Time: Water must sit completely motionless in the plumbing system for a minimum of 6 hours prior to collection.
• Volume & Technique: A first-draw 1-liter (1,000 mL) wide-mouth bottle sample collected immediately upon opening the faucet. Pre-stagnation flushing and aerator removal prior to sampling are strictly prohibited.

Action Level Exceedance Triggers & Corrective Mandates

An Action Level Exceedance is not an immediate violation of an MCL, but triggers mandatory statutory requirements:

1. Optimal Corrosion Control Treatment (OCCT): Install chemical treatment or adjust water chemistry to achieve passivation. Common methods include dosing zinc orthophosphate or polyphosphate corrosion inhibitors (maintaining 1.0 to 3.0 mg/L orthophosphate as $\text{PO}_4$) or adjusting pH/alkalinity with caustic soda, lime, or soda ash to maintain a positive Langelier Saturation Index (LSI).
2. Water Quality Parameter (WQP) Monitoring: Mandatory bi-weekly monitoring of distribution and source water for pH, alkalinity, calcium, conductivity, orthophosphate, and silica.
3. Public Education: Delivery of educational materials regarding lead health risks to all consumers within 60 days.
4. Mandatory Lead Service Line Replacement: Under New Jersey law (P.L. 2021, c. 183), all public community water systems in NJ must inventory and completely replace all lead service lines (both utility-owned and customer-owned portions) within 10 years (by 2031), regardless of whether they experience an Action Level Exceedance.

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8. Consumer Confidence Report (CCR)

Under 40 CFR Part 141, Subpart O and N.J.A.C. 7:10, every Community Water System (CWS) must prepare and distribute an annual drinking water quality report called the Consumer Confidence Report (CCR).

• Statutory Delivery Deadline: The CCR must be delivered to all billing customers and the NJDEP no later than July 1 of each year, reporting data collected during the preceding calendar year.
• Mandatory Content:
  • Identification of raw water sources (aquifers, surface watersheds, reservoirs).
  • Plain-language definitions of MCL, MCLG, MRDL, MRDLG, and Action Levels.
  • A comprehensive table of all detected regulated and unregulated contaminants showing maximum detected levels, ranges, and comparison to regulatory standards.
  • Mandatory educational health language concerning lead and vulnerable populations (infants, pregnant women, immunocompromised individuals).
  • Clear explanation of any violations that occurred during the compliance year, their health significance, and corrective measures taken.

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9. Operational Scenario & Exam Traps

Practical Operational Scenario

A Class 3 surface water treatment plant in northern New Jersey notices elevated TTHM levels (88 ppb) at a remote distribution storage tank sampling tap during the August monitoring round, while the plant effluent TTHM is only 22 ppb. The operator must recognize that TTHM formation is a function of chlorine concentration, precursor TOC concentration, water temperature, and water age.

• Immediate Actions: The operator reviews hydraulic turnover in the storage tank. The tank is currently floating on the system with an average retention time of 9 days.
• Corrective Adjustments: Lower the top operating water level to cycle the tank volume every 48 to 72 hours; install an active mechanical tank mixer to eliminate thermal stratification; install a active diffused aeration stripping system in the tank headspace to volatilize trihalomethanes; and optimize upstream enhanced coagulation to lower raw water TOC before chlorine addition.

Critical Exam Traps

• Trap 1: Confusing MCL with MCLG. An exam question may ask: "What is the Maximum Contaminant Level for Giardia lamblia?" The answer is NOT zero! The MCLG is zero, but the regulatory standard is a Treatment Technique (3-log removal/inactivation). There is no numerical MCL for Giardia.
• Trap 2: Confusing Copper Standards. The health-based Action Level under the Lead and Copper Rule is 1.3 mg/L (1,300 ppb). The aesthetic Secondary Maximum Contaminant Level (SMCL) for copper is 1.0 mg/L (1,000 ppb). Do not mix up the two numbers on certification exams!
• Trap 3: Averaging LRAA across locations. Under Stage 2 DBPR, you can NEVER average results between different sampling stations. The Locational Running Annual Average is calculated strictly at each individual location.
• Trap 4: CCR Delivery Date. The annual CCR delivery deadline is strictly July 1, NOT December 31 or September 30.