MA PHIT- Wastewater Certificate Program · 2013-10-09 · MA PHIT- Wastewater Certificate Program Session 4, Part 1 7 15.203 – Design Flow Design Flow is an Approximate Measure

MA PHIT- Wastewater Certificate Program

Session 4, Part 1 1

Massachusetts Public Health Inspector TrainingWastewater Certificate Program

(MA PHIT WW)

Session 4:

Design and Plan Review—Conventional Systems

Part 1: Septic Tanks and Distribution Boxes

1

Learning Objectives

After 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

MA PHIT- Wastewater Certificate Program, Session 4, Part 1 2

Background



Session 4, Part 1 2

Onsite System Performance

Depends on:1. Proper Design

2. Proper Construction

3. Proper Use, Operation and Maintenance


Plan Review

Why?15.003 (1) 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. Specific site or design conditions, however, may require that additional criteria be met in order to achieve the purpose and/or intent of 310 MR 15.000.


What is in Title 5?

Title 5 Contains Subparts A-F : General Provisions and Enforcement Siting of Systems Design, Construction, Repair and Replacement Inspection and Maintenance Local Upgrade Approval and Variance

Procedures Septage Transport



Session 4, Part 1 3

How Should I Use Title 5?

Create Labelling System by Paragraph with Sections Labelled for: 1. Design Standards2. Construction Standards3. Maintenance Standards4. Enforcement &

Implementation Procedures


What Complications are There?

Science is Evolving Regulations Not Easy to Read Lots of Folklore Processes Happen Out of Sight Designers Can Have More Knowledge or

Experience than Regulators Regional Variation Emotional Subject


How Strict Should I Be Interpreting The Regulation?

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



Session 4, Part 1 4

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.”

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


Completing a Plan Review

Undisturbed Place and Time

Space to Lay Out Information

Copy of Field Notes

Copy of Title 5 and Local Regulations (if any), plus various MassDEP policies

Sensitive Receptor Map

Checklist (suggested)


Checklists

Provide consistency among reviews and reviewers

Adaptable for local bylaws

Several sources: Model

Make your own

Other communities



Session 4, Part 1 5

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”


The Plan Review Process

Steps 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.


Conventional Design

Components

1. Building Sewer

2. Septic Tank

3. Distribution Box

4. Soil Absorption system (SAS)



Session 4, Part 1 6

Non-Conventional Design

May include:

Innovative or Alternative (I/A) technologies

Tight tanks

Shared systems

Variances


Remember

Purpose is to properly Collect Treat Disperse

wastewater


Design Plan Requirements



Session 4, Part 1 7

15.203 – Design Flow

Design Flow is an Approximate Measure of Flow to be Generated

Not Exact (Has Engineering Safety Factor Built In)



Residential flow = 110 gpd Per Bedroom Minimum 330 gpd Design for New Construction For Upgrade can Design for Less Flow, But

Need: a Deed Restriction if # of Bedrooms is Less than 3 Need a Variance if #Bedrooms is Less than 2



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



Session 4, Part 1 8

15.211 –Minimum Setback Distances

Property Line

Building

Wetlands

Wells

Drains

Easements


15.213 – Construction in Velocity Zones and Floodways

Check Plans Against FEMA Flood Maps


15.214-217 – Nitrogen Loading

Applies to New Construction Only

Can Allow 440 gpd/acre (40,000sf) Loading

Site with Well and On-Site Septic is Nitrogen-Sensitive

Zone II and Wellhead Protection Areas

Aggregate Flows Allowed, Procedures Specified



Session 4, Part 1 9

Practice

Pet 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 ft²

2. 75,000 ft²

3. 88,000 ft²


15.220 – Plans and Specifications

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

Legal Bounds and Relevant Easements

Benchmark Not in Area to be Disturbed

Scale Reference Should be Provided

Other Components as Indicated in 15.220

Abandonment Procedures for Existing Septic System as Indicated in 15.354


Designer Stamp

Every 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.



Session 4, Part 1 10

Site Plan and Profile

Site plan Property lines

Right of Ways

Paved surfaces

Buildings/structures

Water lines/wells

Profile To scale

Elevations


Site Plan example


System Profile example




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


Septic Tanks

Functions: Removal of Solids

Bacterial Decomposition

Scum and Sludge Storage


Septic Tanks

Features 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




Septic Tank

Look for: Size, based on flow

Number of compartments

Construction Material

Tees, including drop (inlet to outlet), depth of outlet, and effluent tees

Accessibility


Septic Tanks


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?




15.223 - 229 – Septic Tanks


15.231 Pump Chambers and Controls

If pumping to the Septic Tank, look for: Type of pump (non-grinder preferred)

Two-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


Pump Chamber




Distribution Boxes

Function: 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


15.232 – Distribution Boxes

Look for: Elevations (inlet 2 inches above outlet)

Watertight cover

Minimum 6 inch sump


Session Recap


Documents

MA PHIT- Wastewater Certificate Program · 2013-10-09 · MA PHIT- Wastewater Certificate Program Session 4, Part 1 7 15.203 – Design Flow Design Flow is an Approximate Measure