Milking Center Wastewater: Planning, Design, Construction, Documentation

Transcription

1 Milking Center Wastewater: Planning, Design, Construction, Documentation Peter Wright PE Agricultural Engineer PRO-DAIRY LCBP, NEIWPCC, and EPA are funding partners 1

2 Vermont RAP Section 6. Required Agricultural Practices; Conditions, Restrictions, and Operating Standards 6.01 Discharges a) Farms shall not create any discharge of agricultural wastes to surface waters of the State through a discrete conveyance such as, but not limited to, a pipe, ditch, or conduit without a permit from the Secretary of ANR. b) Production areas, barnyards, animal holding or feedlot areas, manure storage areas, and feed storage areas shall utilize runoff and leachate collection systems, diversion, or other management strategies in order to prevent the discharge of agricultural wastes to surface water or groundwater.

3 NRCS Standards efotg Standards Statements of Work Guidelines Specifications O&M

4 NRCS Standards Filter Strip Standard (VT 393) Heavy Use Area Protection Standard (VT 561) Roofs and Covers (NAT 367) Roof Runoff Structure (VT 558) Waste Treatment (VT 629) Ag Waste Management Supplement Milking Wastewater Infiltration System

5 NRCS O&M OPERATION AND MAINTENANCE PLAN FOR WASTE TREATMENT - MILKHOUSE WASTEWATER INFILTRATION AREA OPERATION AND MAINTENANCE PLAN FOR HEAVY USE AREA PROTECTION

6 Vermont Farm*A*Syst Worksheet #10 Assessing the Risk of Groundwater Contamination from Milkhouse Wastewater Treatment Worksheet #8 Assessing the Risk of Groundwater Contamination from Barn Yard Management

7 Concentrated Sources Waste Wash water Barnyard runoff Silage Leachate

8 Estimated BOD LB/yr Milking Center Waste Silage Leachate Barnyard Runoff Domestic Waste

9 Estimated N LB/yr Milking Center Waste Sila ge Leachate Barnyard Runoff Domestic Waste

10 Estimated P LB/yr Milking Center Waste Silage Leachate Barnyard Runoff Domestic Waste

11 Concentrated Sources Amounts and concentrations vary daily seasonally from farm to farm They can be Managed When Rain Driven the impact is less diluted not observed

12 Concentrations N P Milking Center 400 ppm 60 ppm Silage Leachate 4, Barnyard 1, Manure 5, Domestic Waste 30 7

13 Annual Load from Concentrated Sources N P Milking Center 3,000 lb 30 lb Silage Leachate 3, Barnyard Manure 31,600 5,000 Domestic Waste 70 22

14 Concentrated Sources Pollution is Perception Total load from manure spreading But: Concentrated sources = point sources Concentrated Sources will be closely examined

15

16

17 Resource concern? Volume Concentration Distance Flow path Destination

18 Conclusions Concentrated sources need to be controlled Prevention is key Look for low cost alternatives to treatment

19 Prevention Eliminate Reduce Reuse

20 Wash Water Reduction Eliminate Leaks and Spills Manually rinse or scrape first Reuse gray water Design system for easy cleaning

21 Quantities Range 1-40 gal/cow/day Typical 2-5 gal/cow/day

22 Reduce at the Source Feed Milk First flush Colostrum, treated milk Scrape Manure Parlor and holding area floors Correct Soap Amounts No Precooler Water

23

24

25 Phosphorus Reduction

26 Reuse Wash parlor and holding area floors Water savings Wash cycle water recycled Water savings Soap savings Heat savings

27

28

29 Treatment Aerobic with oxygen Low odors Fast rate By products - Carbon dioxide and water

30 Treatment Anaerobic without oxygen Odors produced Slow rate By products - plug soil pores

31 Liquid Manure System Advantages Easy Low pollution potential Helps manure flow Disadvantages More to haul Larger storage needed

32 Small Holding Tank Figure 5 page 21 DPC 15 / NRAES 115

33

34 Liquid Manure System 1,000 gal. of milkhouse wastes may contain: 1.67 lbs. Nitrogen 0.83 lbs. Phosphorus 2.50 lbs. Potassium 5.00 lbs. of $0.25/lb. = $1.25 Spreading costs: 1,000 $0.005 per gal. = $5.00

35 Grass Filter Advantages Lower cost Efficient treatment Small space Disadvantages Needs O&M Extreme cold weather problems

36

37

38

39 Milking Center Waste Estimated Nitrogen Fate Immobilized Soil OM Denitrified Crop Uptake Leaching Total 68 Lbs. 98 Lbs. 104 Lbs. 55 Lbs. 325 Lbs.N/Acre 1.3 Lbs N/cow /year 250 Cows

40 Milking Center Waste Estimated Nitrogen Fate Immobilized Soil OM 21% Denitrified 30% Crop Uptake 32% Leaching 17% Total 100%

41 Milk House Waste Discharges P Concentration from Pipe Avg mg/l, Range from 2 to 43 mg/l

42 Overall average and range of dissolved P from discharge pipe 40 Dissolved phosphorus, mg/l Modeling the results y = e x R 2 = y = x R 2 = Avg Min Max Stan Dev Linear (Avg) Expon. (Avg) Linear (Max) Expon. (Max) y = e x R 2 = y = x R 2 = Distance from loading source, feet

43 Settling Tank and Pump

44 Dosing siphon

45 Aerobic Lagoon Advantages Storage included Disadvantages Site limitations size, soils Initial cost high Effluent needs further treatment

46

47

48 ORGANIC FILTER BED Advantages Low odors Works in cold weather Disadvantages Potential high cost Potential ground water concerns

49

50

51

52 Constructed Wetland Advantages Politically correct Disadvantages High cost Effluent needs further treatment Hard to establish

53

54

55

56

57 Stone Filled Trench Advantages Works until cold weather Underground Disadvantages High cost Milk must be removed Potential for ground water pollution

58 Lime Flocculated Treatment Advantages Potential low cost Low pollution potential Disadvantages Milk must be removed Process in inside New

59

60

61

62 Wash Water Treatment Plan ahead for expansion Maintenance is important

63 Milking Wastewater Infiltration System (Chapter 10 Vermont Supplement Part (k) Agricultural Waste Management Field Handbook) Components <350 gallons /day Air Trap Air Vent Pipe Settling Tank 6X daily flow Grease Trap Effluent Filter Pump Distribution Box Disposal Field

64

65

66

67

68 Disposal field Design Location Soils investigation Design Class Hydraulic Loading Soil Modification Actual Flow Flow Multiplier Bed Area

69

70 Disposal Field Depth to Bedrock Depth to Hydraulic Restriction Design Class Hydraulic Loading

71 Design Class 1 System is allowed 4 System not allowed 15 to Bedrock 7 to water table or restriction Poor soils

72 Design Class 2 Modify Soil Separation distance 24 to Bedrock 12 to water table or restriction And/or Curtain Drain 12 to water table

73 Design Class 3 Modify Soil Separation distance 24 to Bedrock, water table or restriction And at least 6 of proper fill over sands and gravels

74 Proper Fill Coarse sand to gravelly course sand % gravel 4 8 % fines < 2% clay

75 Actual flow Water meter for two weeks Calculate Range gallons/day/lactating cow

76

77 Flow Multiplier = [ (total suspended solids mg/l + BOD5 mg/l) / 240 ] 1/3 Milkhouse and Parlor (>350 gallons/day) Typical TSS = 6000 mg/l Typical BOD 5 = 1000 mg/l Typical Flow Multiplier = 3.0 Conservative flow Multiplier = 3.0

78

79

80

81 Milking Wastewater Infiltration System O&M Minimize manure, milk and grit Pump out tanks Clean Effluent Filter Inspect for build up at least 2X/Year Safety: Confined Space Grates and guards

82 Conclusions: Concentrated Sources Need to be Controlled Prevention is Key Look for Low Cost Alternatives to Treatment

83