3.01 CLEANING

A. Clean all manholes, intakes and structures by removing sheeting, bracing, shoring, forms, soil sediment, concrete waste and other debris as directed by Jurisdictional Engineer.

B. Do not discharge soil sediment or debris to drainage channels or existing storm sewer or sanitary sewer system.

3.02 VISUAL INSPECTION

A. Examine Structure For:

1. Damage.

2. Slipped forms.

3. Indication of displacement of reinforcement.

4. Porous areas or voids.

5. Proper placement of seals, gaskets and embedments.

B. Verify that structure is set to true line, grade and plumb.

C. Verify structure dimensions and thicknesses.

3.03 REPAIR

A. Repair or replace any unacceptable work at no additional cost to Jurisdiction.

B. Repair all visible leaks.

C. Remove any concrete webs or protrusions.

D. Remove form ties and repair tie holes.

E. Refer also to Section 6010.

3.04 SANITARY SEWER MANHOLE TESTING

A. Method of Test. Subject to Jurisdictional Engineer’s approval.

B. Provide all necessary equipment, supplies and labor to complete required testing.

C. Preliminary test. Conduct preliminary test prior to backfilling manhole, unless waived by Jurisdictional Engineer. Make indicated repairs and adjustments.

D. Conduct final test after manhole construction is complete, all repairs and connections have been made, and invert has been installed.

E. Refer to Iowa Wastewater Facilities Design Standards, Chapter 12, Iowa Standards for Sewer Systems, by Iowa Department of Natural Resources.

F. Infiltration Test: Not allowed for manhole testing.

G. Low Pressure Air Test: Not allowed for manhole testing.

H. Vacuum Test:

1. Applicable only for new manholes isolated from connecting sewer lines.

2. Perform preliminary test after manhole construction is completed and prior to backfilling.

3. Perform final test after backfilling is completed.

4. Use manufactured vacuum test equipment meeting Jurisdictional Engineer’s approval. Follow equipment manufacturer’s recommended procedures throughout, unless directed otherwise by Jurisdictional Engineer or this specification.

5. Use extreme care and follow safety precautions during testing operations. Keep personnel clear of manholes during testing.

6. Seal all openings except manhole top access using pneumatic plugs rated for test pressures. Install plugs according to test equipment manufacturer’s recommendations.

7. Brace pipe inverts if connecting pipes have not been backfilled.

8. Install vacuum tester head assembly on manhole top access, and Inflate seal.

9. Evacuate manhole to 10 inches Hg (mercury) or 5 psi., close isolation valve and start test. Record starting time.

10. Maintain vacuum in manhole for the time indicated in table for the diameter and depth of manhole being tested.

11. Allowable vacuum loss: 1 inch Hg.

12. Test failure is indicated by vacuum loss greater than allowable within the minimum test time indicated in table for the size of manhole being tested.

Test Times for Various Manhole Diameters
Depth, Feet	Diameter, inches
	48	54	60	66	72
	Time, Seconds
8	20	23	26	29	33
10	25	29	33	36	41
12	30	35	39	43	49
14	35	41	46	51	57
16	40	46	52	58	67
18	45	52	59	65	73
20	50	53	65	72	81
22	55	64	72	79	89
24	59	64	78	87	97
26	64	75	85	94	105
28	69	81	91	101	113
30	74	87	98	108	121

I. Exfiltration Test:

1. Applicable for new or rehabilitated manholes.

2. Testing may be performed in conjunction with sanitary sewer lines. Refer to Section 4040.

3. Do not test by this method if temperature of components is below 33 degrees Fahrenheit.

4. Plug inlet and outlet.

5. Hydraulic head for testing: Fill manhole with water to 2 feet above outside top of connecting pipe, but not less than 2 feet above nor more than 5 feet above ground water level.

6. Mark water level.

7. Allow water to stand in manhole for one hour, then refill to original water level and begin test.

8. After one hour, measure the drop in water level. For 48 inch diameter manhole, compare measured water level drop to table, Section 4040, Paragraph 3.06.D to determine equivalent gallons lost per 24 hours. For other manhole sizes, calculate the 24 hour equivalent loss using the formula stated therein.

9. Maximum allowable exfiltration (leakage) per 24 hours: Refer to Section 4040, Paragraph 3.04.

10. Test failure is indicated by water loss greater than maximum allowable exfiltration.

3.05 TEST FAILURE

A. If test fails, reseal openings, repair manhole, and retest. An alternate test method conforming to this specification may be used for a retest if desired.