The Root Of It All

1. The Root Of It All

2. “Tree roots are coming to the forefront as the major cause of sewer spills”

3. “So, how do roots grow?”

4. How Roots Grow • Roots provide structural support and nutrition to the tree • Root growth is similar to tree growth except that roots grow more irregular and tend to be oval as opposed to circular • Roots grow in length and in diameter • Palm roots are the exception • Palm roots grow in length but not in diameter resembling spaghetti

5. How Roots Grow • Typically about 85% of a tree’s roots are within the top 2 feet of soil • To successfully grow roots need moisture, nutrients, and oxygen • Tap roots can grow deep into the soil

6. How Roots Grow • Most of the substantial tree roots stay within the drip line • Feeder roots travel 2 to 10 times the diameter of the drip line • Some aggressive root systems can grow out 100 feet or more from the tree

7. How Roots Grow • Different species of trees vary in how aggressive their root systems are • Some roots systems grow all year round while others have two growing seasons per year • Length of the growing period and the amount of growth is effected by temperature, amount of daylight, water, and soil conditions • Young trees have greater root grow during their growing season than older trees

8. Roots And Sewers • Veil type root structures occur in pipes with a steady flow • Enter from the top or sides of the pipe and hang down like a curtain • Drag along the surface of the water extracting moisture and nutrients • Collect grease and debris within their structure causing blockages • Seldom grow below the water line

9. Roots And Sewers • Tail root structures grow in sewers with low or intermittent flows • Appearance is similar to a horse’s tail • Enter the pipe from the top, sides or bottom • Grow within the pipe in the direction of flow eventually filling the pipe • Can extend in what appears as a solid mass for 20 or more feet within the pipe

10. “Sewers make the perfect gift for roaming tree roots!”

11. Roots And Sewers • Roots are opportunistic • Sewers offer moisture, nutrients and oxygen (kind of a root heaven!) • Sewers provide roots a clear growth path

12. “How do the roots get in the sewers?”

13. Roots And Sewers Through pipe defects (Mains and Laterals)

14. Roots And Sewers • Poor installation is a major cause of defects • Bad pipe bedding • Poor backfilling and compaction • Roots are drawn to leaky sewers • Roots will travel along a sewer line to find a defect to provide an entry point • Aggressive root systems will grow along a sewer line exerting pressure to dislodge a pipe joint or crack the pipe to gain entry

15. Roots And Sewers • Small feeder roots or hair roots can enter through the smallest of cracks or defects • The sewer provides the perfect environment for these small roots to branch out and form root balls • As the feeder roots grow their diameter increases putting additional pressure on the pipe defect they entered

16. Roots And Sewers Small roots become large root balls

17. “So How Do You Get Rid of Dem Roots?”

18. Roots And Sewers • Having an effective maintenance program that includes a root program • Regular routine line cleaning • Utilizing the proper cleaning equipment (mechanical and/or chemical) for pipe type, size and level of root intrusion • Scheduled and spot CCTV inspections to verify line cleaning efforts • Become aware of the types of trees growing along your collection lines and private laterals and how they grow

19. Types of Root Control • Mechanical • Chemical

20. Mechanical Root Control • Achieves instant root removal • Remediates root caused blockages • Types of mechanical root control • Rodding Machine – good on lines up to 12 inch diameter • Jetters or Flushers – use cutter blades or chains rotated by water pressure to cut roots • Bucket Machines – use scrapers designed to cut roots – best for large diameter sewers

21. Mechanical Root Control • Mechanical root cutters commonly become stuck sometimes requiring digging up the pipe to remove them • Cutting roots produces abscisic acid that hastens and thickens regrowth • Frequency of re-cleaning is based upon several factors • Number of laterals • Type and number of trees and root structures • Pipe condition • weather

22. Mechanical Root Control Examples of mechanical root removal tools

23. Chemical Root Control • Use of chemicals is not instantaneous and does not remediate root blockages • Herbicides • Contact herbicides kill roots upon contact • Systemic herbicides are absorbed into the root and travel throughout the plant • Either type of herbicide will kill the root but it may take weeks, months or even years for the root to decay and break off

24. Chemical Root Control Many chemicals such as bensulide, dichlobenil, dinoseb, endothall, metam-sodium, paraquat, trifluralin, 2, 4-D, 2, 4, 5-T, copper sulfate, and chlorthiamid have been used for root control. Also, acid and basic compounds such as sulfamic or sulfuric acid and sodium or potassium hydroxide are commonly used as pour down products in residential settings. Local regulations may prohibit using some chemicals.

25. Chemical Root Control • Application of chemical root control • Pour Down – used primarily by plumbers or homeowners for laterals by pouring chemical down a toilet or cleanout • Foam – pipe is injected with a dense foam that clings to the pipe walls and roots • Spray – normally used on larger lines with good flows where filling the line with foam is to costly or impractical • De-greasers are commonly added to breakdown grease that has collected on the roots

26. Which is best? • Most experts feel that a combination of mechanical and chemical root control is the most effective means to control roots • Mechanically remove the roots followed by applying chemical herbicides • Herbicides are most effective if applied immediately after cutting • Wait for 6 to 8 weeks for the abscisic acid to dissipate before applying herbicides • Effectiveness varies from system to system

27. “What about severe root problems?”

28. Severe Root Problems • Remove the offending trees • Dig and properly replace defective pipe with a pipe that uses welded joints or joints that will not easily crack or separate • Reline the pipe including the lateral connections (Top Hat) • Private lateral maintenance ordinance and/or program (Santa Barbara)

29. “So how are you controlling your roots?”

30. Experiences • Professional Root Control Services • Mechanical root removal • Chemical root control • Self applied chemical root control • Excessive lateral roots • Pushed in roots

31. Thank You Bob Kreg – Project Manager – Dudek Rkreg@dudek.com