Download Dosing Gravity Drainfield Systems

Dosing Gravity Drainfield Systems – NETCHD Standards and Guidance
Effective Date: May 1, 2008
Contents
Page
Introduction........................................................................................................................3
1.
Performance Standards.............................................................................................5
2.
Application Standards ...............................................................................................5
2.1.
2.2.
2.3.
2.4.
3.
Design Standards .......................................................................................................7
3.5.
3.6.
3.7.
3.8.
4.
Listing ..................................................................................................................5
Permitting.............................................................................................................5
Influent Characteristics ........................................................................................6
Pretreatment .........................................................................................................7
Trenches/Beds....................................................................................................10
Monitoring Ports ................................................................................................11
Minimum Design Submittal...............................................................................11
Minimum As-Built Information.........................................................................12
Operation and Maintenance Standards.................................................................13
4.1.
4.2.
4.3.
4.4.
4.5.
Dosing systems ..................................................................................................13
User’s Manual....................................................................................................13
Evaluate septic tank and pump chamber for ......................................................13
Evaluate drainfield area for................................................................................14
Distribution Devices ..........................................................................................14
Glossary of Terms…………….. http://www.doh.wa.gov/ehp/ts/ww/pubs-ww-rsg.htm#glossary
Tables
Table 1. Major Components of Typical Dosing System....................................................... 5
Table 2. Minimum Dosing Frequencies................................................................................ 8
Figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Typical Gravity Drainfield System with Dosing.............................................. 4
Typical Pressurized Flow Splitting Device....................................................... 9
Typical Distributing Valve................................................................................. 9
Typical Monitoring Port Detail....................................................................... 11
Glossary of Terms: A common glossary of terms for all RS&Gs can be found on the DOH
Web site at http://www.doh.wa.gov/ehp/ts/ww/pubs-ww-rsg.htm#glossary. Throughout this
document, new terms introduced that are included in the Glossary appear for the first time in
italics.
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