#611-7 Workbook REVIEW OF PERCOLATION TESTING PROCEDURES. After completing this chapter, you will be able to...

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1 REVIEW OF PERCOLATION 7 TESTING PROCEDURES CHAPTER OBJECTIVES: After completing this chapter, you will be able to... Discuss the purpose of a percolation test. List the regulatory requirements for conducting a percolation test. TEACHING METHOD: Self-study ESTIMATED TIME: 40 minutes MATERIALS / RESOURCES: Computer with Internet access Chapter materials All chapter materials are available at under the Training tab, PSATS SEO Continuing Education, #611, Chapter 7 4 Chapter Study Materials Self-study guide (viewed on the Internet) Workbook (print from the Internet) Answer key (viewed on the Internet) Quiz (viewed on the Internet) 4 Chapter Resources Title 25, Chapters 71-73, regulations (book provided with the Orientation course registration and available on the Internet at com/secure/data/025/025toc.html) Table A Figures 5-1 (Exercise 7-2) and 7-1 and 7-2 (Exercise 7-3) #611-On-Site Revised Testing and Evaluation page 1 Chapter 7 Workbook

2 CHECKLISTS The checklists below are listed to help you organize your training activities. All listed activities should be completed prior to taking the chapter quiz. WORKBOOK ACTIVITIES: 7-1: Percolation Test Hole Locations 7-2: Percolation Test Regulations Review 7-3: Percolation Test Data Review ANSWER KEY: The workbook activity answers may be found in the answer key under under the Training tab, PSATS SEO Continuing Education, #611, Chapter 7, Chapter Study Materials, Course Answer Key. TESTING: The quiz and answers are available online at under the Training tab, PSATS SEO Continuing Education, #611, Chapter 7, Quiz Chapter Quiz: Review of Percolation Testing Procedures #611-On-Site Testing and Evaluation page 2 Chapter 7 Workbook

3 Go to the Chapter 7 Self-Study Guide under under the Training tab, PSATS SEO Continuing Education, #611, Chapter 7, Chapter Study Materials. Begin by reading the objectives for the chapter in the self-study guide. EXERCISE 7-1: Percolation Test Hole Locations For this exercise, you will need to use Figure 5-1, the 5-foot contour map for the mound sites from Exercise 5-1 of Chapter 5. The original plan required additional testing to support a primary and replacement absorption area. In Exercise 5-1, you were to select additional probe test sites on each area and indicate their location on the plan with a solid triangle. Based upon the additional soil test probe locations, locate a six-hole percolation test at both the primary and replacement areas. Indicate the individual percolation test holes by placing small solid circles at the test hole locations within each site. EXERCISE 7-2: Percolation Test Regulations Review Check your familiarity with the percolation test regulations by seeing how many of the following questions you can answer correctly. If you need assistance, refer to Title 25, Chapter ) How should percolation holes be dug? within the absorption area. 2) What are the minimum and maximum limits for the depth and diameter of an individual percolation hole (excluding subsurface sand filters)? a. Depth: to inches b. Diameter: to inches #611-On-Site Testing and Evaluation page 3 Chapter 7 Workbook

4 3) What three factors should determine the depth of the percolation holes? a. _ b. _ c. _ 4) During preparation of the percolation holes, the bottom and sides of each hole should be scarified with a sharp object. Should the loose material be removed from the hole prior to adding the sand or aggregate? YES or NO (circle one) 5) How deep should the coarse sand or fine gravel be placed in the bottom of each percolation hole? inches 6) During the initial presoak, what minimum depth of water should be added to the percolation holes 8 to 24 hours prior to testing? Minimum depth of inches 7) What is the minimum water depth of the final presoak? inches 8) What is established during the last 30 minutes of the final presoak? 9) After the final presoaking period, approximately how many inches over the gravel must the water in the hole be adjusted? inches #611-On-Site Testing and Evaluation page 4 Chapter 7 Workbook

5 10) If a percolation test hole has no water in it after the second presoak, what time intervals apply to the readings taken throughout the test? 11) For the percolation rate to be stabilized (for four consecutive readings), what is the maximum difference allowed between the highest and lowest measurement of those four readings? inch 12) Upon the final reading, if the rate of drop is too slow to obtain a measurable rate, what rate should be assigned? minutes/inch 13) What percolation rate is assigned to a hole that empties out during a 10-minute reading? Note: Title 25, Section 73.15(1) specifies that Six or more tests shall be made in separate test holes... and 73.15(2) specifies that Holes located within the proposed absorption area shall be used in the calculation.... If you started with a six-hole test and you cannot use one hole because it had a fast rate, you now have an insufficient number of holes for calculating the average. An additional hole is required. #611-On-Site Testing and Evaluation page 5 Chapter 7 Workbook

6 EXERCISE 7-3: PERCOLATION TEST DATA REVIEW Figure 7-1 in the Chapter 7 Resources contains a percolation test form with percolation test results. Evaluate both the data entry section and the corresponding calculations on the form. Review each line individually, looking for errors or inappropriate entries. When you encounter an unacceptable entry, note it on the line provided below for each test hole. If everything appears to be in order, enter OK on that line. Use the Percolation Test Hole Conversion Table, Figure 7-2, to confirm interval readings for the measured water level drop in the individual test holes. You do not need to do any calculations for this exercise. PERCOLATION TEST HOLE DATA Hole No. 1 Hole No. 2 Hole No. 3 Hole No. 4 Hole No. 5 Hole No. 6 CALCULATION OF AVERAGE PERCOLATION RATE Hole No. 1 Hole No. 2 Hole No. 3 Hole No. 4 Hole No. 5 Hole No. 6 #611-On-Site Testing and Evaluation page 6 Chapter 7 Workbook

7 Go to under the Training tab, PSATS SEO Continuing Education, #611, Chapter 7, Chapter Study Materials, Course Answer Key, to review the answers to the workbook exercises. Return to the Chapter 7 Self-Study Guide. KEY POINTS: Percolation holes must be evenly spaced throughout the proposed absorption area. The SEO must provide written instructions on site preparation for probe and percolation testing. Percolation holes must be properly prepared and presoaked. Testing must be conducted in accordance with the regulations and the policy of the local agency. #611-On-Site Testing and Evaluation page 7 Chapter 7 Workbook