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Massachusetts Public Health Inspector Training Wastewater Certificate Program (MA PHIT WW). Session 4: Design and Plan Review— Conventional Systems Part 1: Septic Tanks and Distribution Boxes. Learning Objectives. After completing this session (Parts 1 & 2), you will be able to :
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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
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
Background MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Onsite System Performance Depends on: Proper Design Proper Construction Proper Use, Operation and Maintenance MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Plan Review Why? 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? MA PHIT- Wastewater Certificate Program, Session 4, Part 1
What is in Title 5? Title 5 Contains Subparts A-F : • General Provisions and Enforcement, incl. definitions • Siting of Systems • Design, Construction, Repair and Replacement • Inspection and Maintenance • Local Upgrade Approvals and Variances • Septage Transport and Disposal MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Definition Example New construction vs. Upgrade vs. Repair MA PHIT- Wastewater Certificate Program, Session 4, Part 1
How Strict Should I Be Interpreting The Regulation? You set the bar. Designers will rise to the level of professionalism that you establish. MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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 MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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) MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Checklists • Provide consistency among reviews and reviewers • Adaptable for local bylaws • Several sources: • Model • Make your own • Other communities MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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” MA PHIT- Wastewater Certificate Program, Session 4, Part 1
The Plan Review Process Steps Might Include: • Review by Local Health Official • Hearing before BOH • Application to MassDEP • Review by other agencies which are related to the project such as Conservation Commission, Zoning Board, etc. MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Conventional Design Components • Building Sewer • Septic Tank • Distribution Box • Soil Absorption system (SAS) MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Non-Conventional Design May include: • Innovative or Alternative (I/A) technologies • Tight tanks • Shared systems • Variances MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Design Plan Requirements What’s included? MA PHIT- Wastewater Certificate Program, Session 4, Part 1
15.203 – Design Flow • Design Flow is an approximate measure of flow to be generated • Not exact (engineering safety factor built in) MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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? MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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 MA PHIT- Wastewater Certificate Program, Session 4, Part 1
15.211 – Minimum Setback Distances • Property Line • Building • Wetlands • Wells • Drains • Easements MA PHIT- Wastewater Certificate Program, Session 4, Part 1
15.213 – Construction in Velocity Zones and Floodways • Check Plans Against FEMA Flood Maps MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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 allowedwith specified procedures (15. 216) MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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. • 50,000 ft² • 75,000 ft² • 88,000 ft² MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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 MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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. MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Site Plan and Profile Site plan • Property lines • Right of Ways • Paved surfaces • Buildings/structures • Water lines/wells Profile • To scale • Elevations MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Site Plan example MA PHIT- Wastewater Certificate Program, Session 4, Part 1
System Profile example MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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 MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Septic Tanks Functions: • Settling and Separation of Solids • Bacterial Decomposition • Scum and Sludge Storage MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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 MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Septic Tank Look 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 MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Septic Tanks MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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? MA PHIT- Wastewater Certificate Program, Session 4, Part 1
15.223 - 229 – Septic Tanks MA PHIT- Wastewater Certificate Program, Session 4, Part 1
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 MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Pump Chamber MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Distribution Boxes Function: Equal distribution Features & 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 MA PHIT- Wastewater Certificate Program, Session 4, Part 1
15.232 – Distribution Boxes Look for: • Elevations (inlet 2 inches above outlet) • Watertight cover • Minimum 6 inch sump MA PHIT- Wastewater Certificate Program, Session 4, Part 1
Session Recap MA PHIT- Wastewater Certificate Program, Session 4, Part 1