The 10 States Standards: Guidelines for Wastewater Treatment Facilities

Table of Contents

• Introduction
• What They Are
• Key Aspects
• Design Calculations and Examples
• State Adoption
• Industry Benchmark
• Part of a Larger Organization
• Challenges
• Solutions
• Conclusion
• Glossary
• FAQ
• Bibliography

Introduction

In the domain of wastewater engineering, the 10 States Standards provide a detailed compendium of recommendations grounded in empirical data and engineering best practices. These guidelines address critical elements of system design, from hydraulic considerations to biological processes, emphasizing quantitative criteria to achieve optimal performance. Understanding these standards is essential for navigating regulatory approvals and implementing robust designs that mitigate risks to public health and the environment [1].

Note: As of September 23, 2025, the 2014 edition remains the latest for wastewater facilities.

What They Are

The 10 States Standards constitute a technical manual outlining policies, recommendations, and minimum requirements for public wastewater systems. They emphasize engineering rigor, including the use of established formulas for sizing and performance evaluation. The origins trace back to 1947, when the Great Lakes-Upper Mississippi River Board (now GLUMRB) established the Committee on Development of Uniform Standards for Sewage Works, comprising representatives from ten states. This committee reviewed existing standards and explored the feasibility of uniform guidelines to promote consistency across jurisdictions. Based on their initial report, the Board authorized the preparation of sewage works design standards, which were first published in 1951. The purpose was to create a collaborative guide that fosters uniformity in design practices, reduces variability in system performance, and supports regulatory reviews, while accommodating local regulations. The standards were promoted by the GLUMRB and its member states to advance public health and environmental management through shared expertise. Revisions followed in 1960, 1968, 1971, 1973, 1978, 1990, 1997, 2004, and 2014, with the document now including contributions from 10 U.S. states (Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, New York, Ohio, Pennsylvania, Wisconsin) and Ontario, Canada (joined in 1977) [2]. It applies to normal conditions, with provisions for justified deviations, ensuring flexibility in complex projects.

Key Aspects

The standards encompass comprehensive guidance on wastewater treatment and facility design, establishing quantitative minima for analysis. Mandatory elements use "shall," while preferred practices employ "should." Coverage spans engineering reports, hydraulic design, biological processes, disinfection, and sludge handling, all underpinned by calculable parameters to verify compliance.

Key quantitative aspects include:

• Hydraulic design criteria for sewers and force mains, focusing on velocities and friction losses.
• Capacity requirements for pumping stations, emphasizing redundancy and emergency operations.
• Organic loading rates for biological treatment to optimize microbial processes.
• Detention times and dosages for disinfection to achieve pathogen reduction, incorporating chemical reactions such as chlorination and dechlorination.
• Solids retention times for sludge processing to ensure stabilization, with options for chemical pH adjustment.

The standards incorporate chemistry in areas like disinfection and stabilization, specifying chemicals such as chlorine (Cl2), sodium hypochlorite (NaOCl), sulfur dioxide (SO2), and lime (Ca(OH)2). For instance, chlorination involves oxidation reactions where hypochlorous acid (HOCl) forms from Cl2 in water, reacting with organic matter and pathogens: Cl2 + H2O ⇌ HOCl + HCl. Dechlorination uses reducing agents like SO2 to neutralize residuals: SO2 + Cl2 + 2H2O → H2SO4 + 2HCl. pH adjustment for sludge stabilization employs alkaline additions to raise pH above 12, inhibiting microbial activity through hydroxide ion (OH-) effects [2].

The following tables summarize select design criteria across major sections, drawn from the 2014 edition and grouped by focus subjects. These serve as benchmarks for preliminary sizing and hydraulic modeling.

Hydraulic Design (Sewers and Force Mains)

Pumping Stations

Biological Treatment

Chemical Disinfection and Stabilization

These criteria facilitate detailed engineering analyses, such as hydraulic profiling and process modeling [3].

Design Calculations and Examples

The standards incorporate numerous calculations for verification. Below, we explore key examples and reasoning. These can be applied in software like EPANET.

The standards often incorporate conservative factors in their tabulated values to account for real-world conditions such as partial flows or variations in roughness coefficients. This can lead to discrepancies between direct theoretical calculations and recommended minima, ensuring safety and reliability in practice.

Manning's Equation for Sewer Slope

Used to determine minimum slope (S) for self-cleansing velocity.

Equation (English units): $V=\frac{1.486}{n}{R}^{2/3}{S}^{1/2}$

Where:

• $V$ = velocity (ft/s)
• $n$ = Manning's roughness (0.013 for concrete/PVC)
• $R$ = hydraulic radius (ft) = D/4 for full circular pipe
• $S$ = slope (ft/ft)

Example: For an 8-inch (0.667 ft diameter) sewer, find min $S$ for $V$=2 ft/s.

1. Calculate R: R = 0.667 / 4 = 0.167 ft
2. R^{2/3} = (0.167)^{2/3} ≈ 0.303
3. Rearrange for S^{1/2}: S^{1/2} = (V n) / (1.486 x R^{2/3}) = (2 x 0.013) / (1.486 x 0.303) ≈ 0.026 / 0.450 ≈ 0.058
4. S = (0.058)^2 ≈ 0.0033 ft/ft ≈ 0.33 ft/100 ft

Note: While this calculation yields approximately 0.33 ft/100 ft, the standards specify 0.40 ft/100 ft to incorporate conservatism for partial flows or higher n values. Always use the recommended value unless site-specific data justifies adjustment [2].

Hazen-Williams for Force Main Friction

Equation: Head loss h_f = (10.67 L Q^{1.852}) / (C^{1.852} D^{4.87}), where L=length (ft), Q=flow (cfs), D=diameter (ft), C=coefficient.

Alternatively, velocity form: $V=1.318C{R}^{0.63}{S}^{0.54}$

Example: For a 4-inch (0.333 ft) force main, L=1000 ft, Q=0.1 cfs (peak), C=120.

1. Q^{1.852} ≈ 0.1^{1.852} ≈ 0.015
2. D^{4.87} ≈ 0.333^{4.87} ≈ 0.0015
3. C^{1.852} ≈ 120^{1.852} ≈ 10200
4. h_f = (10.67 x 1000 x 0.015) / (10200 x 0.0015) ≈ 160 / 15.3 ≈ 10.5 ft

This assists with pump selection and energy analysis [2].

Biological Loading Rate

For activated sludge: Loading = (BOD5 influent x Q x 8.34) / (MLSS x V_tank), target 0.2-0.5 lb. BOD5/lb. MLSS/day (conventional).

Example: Influent BOD5=200 mg/L, Q=1 MGD, MLSS=3000 mg/L, find required V_tank for 0.3 loading.

1. BOD5 mass = 200 x 1 x 8.34 = 1668 lb./d
2. MLSS mass = 3000 x V (MG) x 8.34 = 25020 V lb.
3. 1668 / (25020 V) = 0.3 → V = 1668 / (0.3 x 25020) ≈ 0.22 MG

Such calculations optimize reactor sizing and aeration [2].

Additional Example: Trickling Filter Hydraulic Loading

For standard rate filters: Hydraulic loading ≤ 100 gpd/ft², organic loading ≤ 15 lb. BOD5/d/1000 ft³.

For 10,000 ft² filter area, influent flow 0.5 MGD (500,000 gpd), check compliance.

1. Loading = 500,000 / 10,000 = 50 gpd/ft² < 100, compliant
2. For BOD5=200 mg/L, mass = 200 x 0.5 x 8.34 ≈ 834 lb./d
3. Volume needed at 15 lb./1000 ft³: 834 / 15 x 1000 ≈ 55,600 ft³
4. With 20 ft depth: Area = 55,600 / 20 = 2,780 ft² < 10,000, overdesigned for safety

This ensures even distribution and performance [2].

Chemical Dosage for Dechlorination

Equation: SO2 dosage ≈ 0.9 x Cl2 residual (mg/L), based on reaction stoichiometry.

Example: For effluent with 2 mg/L Cl2 residual, flow=1 MGD, calculate daily SO2 mass.

1. Dosage = 0.9 x 2 = 1.8 mg/L
2. Mass = 1.8 x 1 x 8.34 ≈ 15 lb./d

Adjust for complete neutralization, monitoring residual to prevent excess sulfite [2].

These examples demonstrate how standards translate to actionable design, encouraging use of tools like Python for iterative solving.

State Adoption

The standards are adopted voluntarily but integrated into regulations by member jurisdictions, requiring quantitative demonstrations in submittals. Professionals must verify local amendments, such as enhanced nutrient limits in sensitive watersheds [4].

Industry Benchmark

As a de facto standard, they promote uniformity through calculable metrics, enabling benchmarking via performance models. Their technical focus supports advanced simulations, fostering innovation in areas like nutrient recovery.

Part of a Larger Organization

Issued by the GLUMRB, the standards leverage collective expertise for evidence-based criteria. Companion water works standards (2022 edition) provide parallel guidance for integrated water management [1].

Challenges

Challenges include adapting calculations to variable influents, integrating newer technology such as membrane bioreactors, and computational demands for large systems. Aging infrastructure may require retrofits exceeding minima.

Solutions

Employ modeling software for scenario analysis, early regulatory engagement, and pilot testing to validate deviations.

Conclusion

The 10 States Standards equip us with technical tools for designing resilient wastewater systems. By using calculations you can advance from conceptual to detailed engineering, contributing to sustainable infrastructure. Consult official documents for full context and updates.

Glossary

• ASTM: ASTM International - Organization developing standards for materials and testing.
• BOD: Biochemical Oxygen Demand - Measure of the amount of oxygen consumed by microorganisms in breaking down organic matter.
• BOD5: Five-day Biochemical Oxygen Demand - Measure of organic load (mg/L or lb./day).
• Ca(OH)2: Calcium Hydroxide - Chemical used for pH adjustment and sludge stabilization.
• CaO: Calcium Oxide - Quicklime, used in high pH stabilization processes.
• cfs: Cubic Feet per Second - Unit of flow rate.
• Cl2: Chlorine - Gas used for disinfection in wastewater treatment.
• DO: Dissolved Oxygen - Critical for aerobic processes (mg/L)
• ft/s: Feet per Second - Unit of velocity
• GLUMRB: Great Lakes-Upper Mississippi River Board of State and Provincial Public Health and Environmental Managers - Organization responsible for the standards.
• gpd: Gallons per Day - Unit of flow rate.
• gpd/ft²: Gallons per Day per Square Foot - Unit for hydraulic loading.
• HCl: Hydrochloric Acid - Byproduct in chlorination reactions.
• HOCl: Hypochlorous Acid - Active disinfectant formed from chlorine in water
• H2SO4: Sulfuric Acid - Byproduct in dechlorination reactions.
• lb. BOD5/d/1000 ft³: Pounds BOD5 per Day per 1000 Cubic Feet - Unit for organic loading.
• lb./capita/day: Pounds per Capita per Day - Unit for loading rates.
• m/s: Meters per Second - Unit of velocity.
• MGD: Million Gallons per Day - Unit of flow rate.
• mg/L: Milligrams per Liter - Unit of concentration.
• MLSS: Mixed Liquor Suspended Solids - Biomass concentration in activated sludge (mg/L).
• NaOCl: Sodium Hypochlorite - Liquid bleach used for disinfection.
• OH-: Hydroxide Ion - Involved in pH adjustment and alkaline hydrolysis.
• SO2: Sulfur Dioxide - Chemical used for dechlorination.
• SRT: Solids Retention Time - Average time solids remain in a system (days).

FAQ

Q: How do I apply Manning's equation in design software?
A: Input n=0.013, solve for S given V_min and D; validate against table values.

Q: Are there updates post-2014?
A: As of 2025, no; monitor GLUMRB for revisions.

Q: Can I deviate from criteria?
A: Yes, in theory, with justification and approval, supported by calculations. Be aware that approved deviations are rare in my experience.

Q: Where to access the full standards?
A: https://www.health.state.mn.us/communities/environment/water/tenstates/standards.html

Bibliography

1. https://www.health.state.mn.us/communities/environment/water/tenstates/standards.html
2. https://extapps.dec.ny.gov/fs/projects/spdes/TenStateStrdsWastewater.pdf
3. https://epa.ohio.gov/static/Portals/35/pti/10wastewaterstandards-2014.pdf
4. https://www.kuritaamerica.com/the-splash/10-state-standards-update