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What are the minimum soil depths for permitting a shallow conventional, LPP, and mound system in group I and IV soils?
- 18” ss and
- 12”+ SHWT
Wetlands on farms are regulated by ________?
Natural Resources Conservation Service
How do Division of coastal management representatives determine if a property contains wetlands?
A property (or portion of property) contains wetland plants when greater than ______ % of plants are OBL, FACW or FAC
Obligate wetland plants occur in wetlands _____ percent of time
more than 99%
Facultative wetland plants usually occur in wetland ___ to ____ % of the time
67 - 99
List two examples of secondary indicators of wetland hydrology
Oxidized rhizosphere in upper 12” of living roots, water stained leaves, soil survey data, FAC neutral test (greater than 50% of dominant non-FAC plants are wetter than FAC)
List two examples of primary indicators of wetland hydrology
Visual observation of inundation,
- saturation within 6-12”,
- water marks,
- drift lines, s
- ediment deposits,
- drainage patterns
Name two federal and two state agencies that regulate wetlands
- Army Corps of Engineers,
- Natural Resources Conservation Service;
- NC Division of Water Quality,
- NC Division of Coastal Management
What is the difference between wetland restoration and wetland creation?
Wetland restoration is the ones that were wetlands and and wetland creations were not.
List three examples of major anthropogenic (man caused) wetland destruction/alterations
1) Deforestation/filling/draining for construction
- 2) Clearing/draining for agriculture
- 3) Urban stormwater runoff and eutrophication
- 4) Wastewater loading and eutrophication
List four common wetland communities in NC
- bottomland hardwood forest,
- swap forest,
- shrub forest
What % of the US population lives in coastal areas?
List 4 reasons wetlands are important?
- rare species habitat
- remove nutrients
- Stores flood waters
Wetlands account for what % of land area in lower 48 states, what % of NC?
Wetlands must have what three things:
Soil, Wetland Hydrology, Wetland vegetation
Low chroma colors are indicative of what limiting condition?
Seasonal High Water Table
What are two unsuitable landscape positions
Wetlands, Sloap more than 65%, depressions
List two soil types for each soil group
- Sand, Loamy Sand
- Sandy Loam, Loam
- Sandy Clay Loam, Silt, Silty Clay Loam
- Clay, Silty Clay
How far must on-site systems be from a stream, swimming pool, and property line?
- 50 to 100 to a stream,
- 15 to a pool
- 10 to a property line
If the soil in question 19 was a group IV instead of group III and was 20” deep, what system would you recommend and why?
LPP because if it was a group 4 instead of a group 3, the space needed for the .1 loading rate would be massive
If the limiting condition for the site in question 18 was 20” what other option would you have, and would you recommend it - why/why not?
you could have an LPP system because it would lower the space needed, however LPP needs to be maintained so it can become expensive
If you perform a soil evaluation and determine that the limiting condition is 19”, and the soil is a group III, what system type and application rate would you suggest?
You just graduated and are now working with a county health department ( I told you someone in class would do this), you just completed a soil evaluation for a permit applicant. The soil was 36” deep to low chroma colors and the soil between 24” and 36” would produce a ribbon 2.5” long, and had a smooth feel. What texture and soil group was this sample?
Silty Clay group 4
If you have a soil with a 0.5 g/d/ft2 LTAR and a 3 BR house, how much FT2 will a conventional system require? What if you use a chamber?
25% reduction so multiply by 75%
What are the benefits of using an LPP?
better distribution, 25-30% less space, soil depth less than usual
What are the benefit of using a chamber and polystyrene relative to a conventional?
25% reducion in space, easier to install
List 4 types of septic systems?
LPP, Shallow Conventional, Mound, Conventional
What is the design flow for a 2 BR, 3 BR and 4 BR?
240, 360, 480
What does LTAR stand for?
Long Term Loading Rate
______ clays are suitable for on-site systems, while ______ clays are unsuitable
three examples of unsuitable soil structure
- Angular blocky
What method is used in the field to determine soil partical size distribution and soil group status?
texture by feel
two physical, chemical and biological treatment mechanisms in soil
- physical - Filtration, dispursion
- Chemical- evaporation, cat ion exchange
- Biological - Nitrification, Oxidation
List the four major components of an on-site wastewater systems and describe what each component does
1) Septic tank- settling tank, removes solids, dissipates energy, digests organic matter, converts ON to NH4
- 2) Distribution device- distributes wastewater to drainfield trenches
- 3) Drainfield trenches- stores wastewater until wastewater infiltrates soil
- 4) Soil- provides physical, chemical and biological treatment of wastewater
What are average septic effluent concentrations of total nitrogen, total phosphorus and fecal coliform?
- 26-75 - total nitrogen
- 6-12 - total p
- 10^8 - fecal coliform
How many on-site systems are installed each year?
30,000 to 40,000
What % of the US and NC population uses on-site wastewater systems?
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