Massachusetts Public Health Inspector Training Wastewater Certificate Program (MA PHIT WW)

Massachusetts Public Health Inspector

TrainingWastewater Certificate

Program (MA PHIT WW)

Session 4:Design and Plan Review—

Conventional SystemsPart 1:

Septic Tanks and Distribution Boxes

1

MA PHIT- Wastewater Certificate Program, Session 4, Part 1

Learning ObjectivesAfter completing this session (Parts 1 & 2), you will be able to: List functions and features of onsite wastewater

components Describe a conventional onsite wastewater

system layout Explain design plan requirements Analyze elements of design plans Determine appropriate steps to take after

completing a plan review

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Background

3


Onsite System Performance

Depends on:1. Proper Design2. Proper Construction3. Proper Use, Operation and Maintenance

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Plan ReviewWhy?15.003 (1)--…full compliance with the provisions of 310 CMR 15.000 is presumed…..to be protective of the public health, safety, welfare and the environment.

What are some challenges BOH face?

5


What is in Title 5?

Title 5 Contains Subparts A-F :A. General Provisions and Enforcement, incl.

definitionsB. Siting of SystemsC. Design, Construction, Repair and ReplacementD. Inspection and MaintenanceE. Local Upgrade Approvals and VariancesF. Septage Transport and Disposal

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Definition Example

New construction vs. Upgrade vs. Repair

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How Strict Should I Be Interpreting The

Regulation?You set the bar.

Designers will rise to the level of professionalism that you establish.

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Key Plan Review Components - The “Big Picture”

Remember the Goal: Section 003(1) states: “In general, full compliance with the

provisions of 310 CMR 15.000 is presumed by the Department to be protective of the public health, safety, welfare and the environment.”

What’s the difference between LUA and variance?

This Does Not Require That You Are Responsible for Making the Designer or Owner Pleased With the Results of Your

Review

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Completing a Plan Review Undisturbed place and

time Space Copy of field notes Copy of Title 5 and local

regulations (if any), plus various MassDEP policies

Maps (such as sensitive receptors)

Checklist (suggested)

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Checklists Provide consistency

among reviews and reviewers

Adaptable for local bylaws

Several sources:B̶Model B̶Make your ownB̶Other communities

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The Plan Review Process—DSCP

Design plan should be submitted with a partially completed Disposal Systems Construction Permit Application (DSCP)

Technically, are not reviewing the Plan, but are reviewing the DSCP (15.020)

Actions taken to accept or deny a design plan should reference “DSCP and accompanying Design Plan”

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The Plan Review ProcessSteps Might Include:1. Review by Local Health Official2. Hearing before BOH3. Application to MassDEP4. Review by other agencies which are related

to the project such as Conservation Commission, Zoning Board, etc.

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Conventional DesignComponents1. Building Sewer2. Septic Tank3. Distribution Box4. Soil Absorption

system (SAS)

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Non-Conventional Design May include: Innovative or Alternative

(I/A) technologies Tight tanks Shared systems Variances

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Design Plan Requirements

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What’s included?


15.203 – Design Flow Design Flow is an approximate measure of

flow to be generated Not exact (engineering safety factor built in)

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15.203 – Design Flow

Residential flow = 110 gpd per bedroom Minimum 330 gpd for new construction

Exception: with deed restriction, can be 220 gpd Can new construction be designed for 1

bedroom? What about an upgrade?

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15.203 – Design Flow

Upgrade is to be designed for what currently exists on the property and some flexibility is allowed

Additional flow above what was historically approved or what exists on the property requires compliance with new construction standards

Currently vacant parcel triggers new construction standards

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15.211 – Minimum Setback Distances Property Line Building Wetlands Wells Drains Easements

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15.213 – Construction in Velocity Zones and

Floodways Check Plans

Against FEMA Flood Maps

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15.214-217 – Nitrogen Loading

Applies to new construction only in nitrogen sensitive areas Site with a well and on-site septic system Zone II and Wellhead Protection Areas

Can allow 440 gpd/acre (40,000sf) Aggregate flows allowed with specified

procedures (15. 216)

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Practice

Per Title 5, 1 acre = 40,000 ft² Calculate maximum gpd for the following size

residential lots. Assume new construction in a nitrogen sensitive area with no enhanced nitrogen removal.1. 50,000 ft²2. 75,000 ft²3. 88,000 ft²

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15.220 – Plans and Specifications

Who can submit a plan? What is on the plan?

B̶Legal Bounds and Relevant EasementsB̶Benchmark Not in Area to be DisturbedB̶Scale Reference Should be ProvidedB̶Other Components as Indicated in 15.220B̶Abandonment Procedures for Existing Septic System as Indicated in 15.354

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Designer StampEvery plan submitted for approval must be dated and bear the stamp and signature of the designer.At least one copy submitted shall bear the original stamp and signature of the designer.

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Site Plan and ProfileSite plan Property lines Right of Ways Paved surfaces Buildings/structures Water lines/wellsProfile To scale Elevations

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Site Plan example

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System Profile example

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15.222 – Building Sewers

4” Minimum Diameter Laid on Compacted Firm

Base Slope (1% min) Continuous Grade in

Straight Line Manholes at Junctions &

Cleanouts at 100' Intervals

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Septic TanksFunctions: Settling and Separation of

Solids Bacterial Decomposition Scum and Sludge Storage

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Septic TanksFeatures and Elements: Watertight Precast concrete or MassDEP approved material Sewage enters thru inlet tee Solid and Scum separation (solids settle at

bottom and floatables or scum rises to top) Clarified effluent exits thru outlet tee Dimensions specified in Title 5

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Septic TankLook for: Size, based on flow

1500 gal minimum 200% of design flow or 48 hour detention

Number of compartments Construction Material Tees, including drop (inlet to outlet),

depth of outlet, and effluent tees Accessibility

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Septic Tanks

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15.223 - 229 – Septic Tanks Size to be 200% of the Design Flow with a

Minimum 1,500 Gallon Capacity 2-Compartment Tank if Serving >2 Dwellings, daily

flow > 1,000 gpd, or with a Garbage Grinder Construction Specifications should be on the plan,

Including One Cover to Within 6” of Final Grade Tee Placement Access Ports and Manholes

Is an effluent filter required if a pump is present?

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15.223 - 229 – Septic Tanks

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15.231 Pump Chambers and Controls

If pumping to the Septic Tank, look for:B̶Type of pump (non-grinder preferred)B̶Two-compartment septic tank, emergency power, alarms, and 24 hr. storage capacity if pumping >25% of the design flow

Compliance with Plumbing Code One 20” Manhole with Cover Located at Final

Grade

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Pump Chamber

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Distribution BoxesFunction: Equal distributionFeatures & Elements Concrete or other approved

material Base to be level and stable Tee Required When >8%

Slope or Pump Outlet Lines Level for First 2’ Risers to near finished grade One Outlet Per Line

Photo courtesy of University of Rhode Island Onsite Wastewater Resource Center

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15.232 – Distribution BoxesLook for: Elevations (inlet 2 inches above outlet) Watertight cover Minimum 6 inch sump

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Session Recap

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Documents

Massachusetts Public Health Inspector Training Wastewater Certificate Program (MA PHIT WW)