6/8/2012

1

Groundwater Current

Events

New policies- New problems- New criteria

Three main topics

� New policy- Electronic reporting

� New Problem- What’s with the focus on BOD?

� New Criteria- Michigan Criteria For Subsurface Disposal

6/8/2012

2

Electronic Reporting

6/8/2012

3

Write down this address� https://secure1-qz.state.mi.us/e2rs/

� Or www.michigan.gov/deq and click on online services

6/8/2012

4

Why are they asking for BOD? � The mystery of the red slime

Presentation of evidence (I)�The story of a food processor

� sugar water

� Odor complaints

� COD measured in monitor wells

� Ponding and pooling in fields

6/8/2012

5

Presentation of evidence (I)�The story of a food processor

� sugar water

� Odor complaints

� COD measured in monitor wells

� Ponding and pooling in fields

� Slimy red water and rust

6/8/2012

6

6/8/2012

7

Remember redox reactions?� Iron + water + air = rust

� Fe + H2O + O2 = FeO3 + 2H

6/8/2012

8

Presentation of evidence (II)�The story of a food processor

� sugar water

� Odor complaints

� COD measured in monitor wells

� Ponding and pooling in fields

� Slimy red water and rust

- BOD

- BOD

- BOD

Anaerobic conditions

Focus on BOD � Anaerobic conditions in surface water?

� For a groundwater discharge- What happens if oxygen depleted in soil?

6/8/2012

9

Aerated soil particle

Fe3+

(Ferric oxide or

Iron sulfide)

Mn4+

(Manganese dioxide)

As

N

O2

O2

CO2

CO2N

O2

Soil with BODFe3+

Mn4+

Al

As

O2

CO2

O2

BOD critter

O2

O2

6/8/2012

10

Soil with BOD-anoxic condition

Fe3+

Mn4+

Al

As CO2

???

A friendly chemical equilibrium reaction for you!

� 2FeS2 + 7O2 + 2H2O (insoluble iron pyrite)

� 2Fe 2+ + 4SO42- + 4H+ (soluble iron sulfate)

6/8/2012

11

Soil with BOD- using O2 from minerals

2 Fe 2+ + (4SO42-) + 4H

(soluble iron sulfate)

Mn4+

Al

As CO2

O2

(4SO42-)

Presentation of evidence (III)�The story of a food processor

� sugar water

� Odor complaints

� COD measured in monitor wells

� Ponding and pooling in fields

� Slimy red water

- BOD

- BOD

- BOD

Anaerobic conditions

Soluble iron and other metals

6/8/2012

12

How to respond to the problem?� BOD concentration

� Land area

� Permeability

� Ideal BOD loading rate?? (not really known)

50 lbs BOD per acre per day

Current events #3� Rewrite of the Michigan Criteria

6/8/2012

13

Michigan Criteria Update� Used for sewage flow up to 20,000 GPD

� Recall flows >6,000 GPD needs

authorization

� Range of suitable soils expanded

� No perc testing. Use table values for hydraulic loading

� Gravity distribution only acceptable in systems < 1,000 GPD

� Major changes in basis of design for flow

6/8/2012

14

Michigan Criteria Update� Changes required depth to groundwater (3 ft.

to groundwater instead of 4 ft.) Also allows for “alternative treatment”

� 18 inches of undisturbed soil to high groundwater

� Simple septic/tile field not allowed for >6,000 GPD flows

� Wastewater strength assessment required.

� Process for determining aquifer vulnerability.

6/8/2012

15

Questions?