HomeMy WebLinkAboutAppendix F - Sea Level Rise Map and BURBS Analysis
The Enclaves Projected 6-Foot Sea Level Rise
0 0.25 0.50.125
mi
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Subject Property
0-to-6-Foot Projected Sea Level Rise
THE ENCLAVES
56655 ROUTE 25 (AKA MAIN ROAD)
SOUTHOLD, NEW YORK
TAX MAP: 1000-063.00-03.00-015.000
MARCH 2019
BURBS
NITROGEN LOADING MODEL
PREPARED FOR:
Andrew V. Giambertone & Associates
62 Elm Street
Huntington, New York 11743
PREPARED BY:
P.W. Grosser Consulting, Inc.
630 Johnson Avenue, Suite 7
Bohemia, New York 11716
Phone: 631-589-6353
Fax: 631-589-8705
Bryan Grogan, PE – Vice President bgrogan@pwgrosser.com
PWGC Project Number: AVG1803
Purpose
The purpose of this report is to document the findings of a nitrogen mass balance prediction performed
by P.W. Grosser Consulting (PWGC) for the evaluation of environmental impacts of the proposed
restaurant and hotel development. The proposed development includes 6.75 acres of currently developed
property in the Town of Southold, Suffolk County, New York. The project area is located north of Main
Road, and is approximately 1,000 feet north of Town Creek/Southold Harbor. The proposed development
consists of a 74 seat restaurant and 44 unit hotel.
Nitrogen Mass Balance Prediction
PWGC has evaluated the expected nitrogen loading to groundwater under several land use scenarios
using the BURBS model. The BURBS model, developed at Cornell University by Hughes et al. (1985), is a
computer simulation program that computes the potential impact of various land use on
groundwater within a community due to nitrogen. Cornell University has developed this model for specific
application on Long Island. For comparative purposes, PWGC has prepared a BURBS computation for four
land use scenarios: historic conditions, existing conditions, alternate plan and proposed development
plan. Based on PWGCs experience, this program will predict a conservative estimate of nitrogen recharged
to groundwater. It calculates loadings from wastewater, turf/landscaped land, natural land, runoff from
impervious surfaces and atmospheric deposition. Each of these parameters is discussed and model
parameters are defined.
There are 18 parameters used in the BURBS model:
1. Fraction of Land in Turf
2. Fraction of Land which is impervious
3. Average persons per dwelling
4. Housing density
5. Precipitation rate
6. Water recharged from turf
7. Water recharged from natural land
8. Evaporation from impervious surface
9. Runoff from impervious recharged
10. Home water use per person
11. Nitrogen concentration in precipitation
12. Nitrogen concentration in water used
13. Turf fertilization rate
14. Fraction of nitrogen leached from turf
15. Fraction of wastewater N lost as gas
16. Wastewater fraction removed by Sewer
17. Nitrogen per person in wastewater
18. Nitrogen removal rate of natural land.
Determining Constant Parameter Values
These parameters were constant across all scenarios: items 5-12, 14, and 16-19. Note that in some
cases, certain parameters do not apply, but are still considered constant. For instance, the water
recharged from turf is considered a constant parameter even in scenarios where there is no turf area.
These parameters are summarized in Table 1, below:
Table 1 – BURBS Constant Parameters
BURBS Parameters
Burbs
Inputs Units
5. Precipitation rate 47 inches/year
6. Water recharged from turf 35.25 fraction
7. Water recharged from natural land 23.5 fraction
8. Evaporation from impervious surface 0.1 gallons/day
9. Runoff from impervious recharged 1 fraction
10. Home water use per person 100 gallons/day
11. Nitrogen concentration in precip. 0.71 lbs/1000 sq ft
12. Nitrogen concentration in water used 5.18 fraction
14. Fraction of nitrogen leached from turf 0.3 fraction
16. Wastewater fraction removed by Sewer 0 fraction
17. Nitrogen per person in wastewater 10 lbs/year
18. Nitrogen removal rate of natural land 0.9 fraction
Precipitation Rate (5)
The annual average precipitation in inches (BURBS). A value of 47 inches was used for this project. This is
a typical rainfall amount for Long Island.
Water recharged from Turf (6)
The amount of water per unit area of turf which drains to groundwater (BURBS). Based upon PWGCs
experience and Long Island geology, approximately 50% of rainfall is recharged. However, to account for
the turf areas being irrigated and the possibility of soil saturation the recharge percentage was
increased to 75%. Therefore, 35.25 inches per year was used for water recharged from turf.
Water recharged from Natural Land (7)
The amount of water per unit area of turf which drains to groundwater (BURBS). Based upon PWGCs
experience and Long Island geology, approximately 50% of rainfall is recharged. Therefore, 23.50 inches
per year was used for water recharged from natural land.
Evaporation from Impervious Surfaces (8)
The fraction of precipitation falling on impervious surface assumed to evaporate (BURBS). A value of .1
was used for each of the models run. This amount is recommended by the BURBS parameter
description.
Runoff from Impervious Recharged (9)
The fraction of the runoff which is recharged through recharge basins, ponds, etc (BURBS). Evaporation
is subtracted. All the runoff for this project area will be directed to the subsurface. Therefore, a value of
1 was used in each of the models run.
Home Water Use per Person (10)
Average in-home use of water (BURBS). The value used here was 100 gallons per person. This value was
based on the Suffolk County Department of Health Services (SCDHS) estimate of 300 gallons of water
use per day per single family home. Using the NP&V value of 2.5 persons per dwelling (rounding up to
3), and dividing by the number of persons per dwelling, yields approximately 100 gallons used per
person. This is conservative estimate and includes all water uses such as bathing, sanitary, irrigation, etc.
Nitrogen Concentration in Precipitation (11)
Average concentration. The Burbs models recommends using data from the closest weather station
where nitrogen tests were taken (BURBS). An average value of 0.71 mg/L was used in each of the BURBS
models run. This was derived from the National Atmospheric Deposition Program NTN Site NY96 - Cedar
Beach, Southold, New York. Concentration of nitrate (NO3) were given as an annual average for the
years 2003 through 2017, ranging from 0.43 mg/L to 0.92 mg/l.
Nitrogen Concentration in Water Used (12)
Average concentration in water used in homes (BURBS). A value of 5.18 mg/L was used when running
each of the models. This value was taken from the Suffolk County Water Authority (SCWA) 2018 Drinking
Water Quality Report – Distribution Area 30, p. 45.
Fraction of Nitrogen Leached from Turf (14)
The fraction of nitrogen applied from fertilizer, precipitation, etc. which leached to groundwater. The
BURBS model recommends 0.35 for sandy soil if clippings are removed, or 0.5 if clippings are left on turf.
We used 0.30, a comparable value, from the Long Island Nitrogen Loading Model.
Fraction of Wastewater Removed by Sewer (16)
The efficiency of sewer systems. If no sewers are present, use 0 (BURBS). There are no sewers present at
this site, thus the fraction of wastewater removed by sewers is 0.
Nitrogen per Person in Wastewater (17)
The average in the United States is 10 pounds per person per day (BURBS). This value was used when
running the BURBS model in all scenarios.
Nitrogen Removal Rate of Natural Land (18)
The fraction of nitrogen in precipitation which is removed by natural land before the water is recharged.
Should be at least 90 percent (BURBS). Based upon the recommendations made by the BURBS
parameter description, a value of 0.9 was used for all scenarios.
Determining Variable Parameter Values
These parameters vary by scenario: items 1-4, 13 and 15. These parameters are summarized in Table 2,
see below:
Table 2– BURBS Variable Parameters
56655 Route
25
Southold, NY
Area
BURBS Inputs
1.
Fraction
Turf
2. Fraction
Impervious
3.
Average
Persons
Per
Dwelling
Number
of
Dwellings
4.
Housing
Density
13.
Turf/Agriculture
Fertilization
Rate
15. Fraction
of
wastewater
N lost as gas
Scenario acre fraction fraction persons dwellings dwellings
/acre lbs./1000 sq ft fraction
Historic
Conditions 6.75 0.87 0 3 1 0.15 1.86 0.50
Existing
Conditions 6.75 0.14 0.02 3 1 0.15 2.04 0.50
Alternate Plan 6.75 0.34 0.66 3 13.45 1.99 2.04 0.50
Proposed
Development 6.75 0.53 0.44 3 29.40 4.35 2.04 0.85
Fraction of Land in Turf, Impervious, and Natural (1, 2)
The fraction of land in turf refers to areas maintained as lawn. The fraction of land which is impervious is
the sum of roof areas, driveways, and roads. Both the fraction of land in turf and impervious must be
between 0 and 1. The fraction of land in natural vegetation is computed as 1 minus the sum of the
fraction in turf and impervious, thus the sum of these must be less than 1 (BURBS). The historic land
area was estimated from historical aerials found on the Suffolk County government website. In the
existing conditions scenario, all area was classified as natural area. For the proposed development and
alternate plan, the land areas were derived from the proposed grading and drainage plans.
Average Persons per Dwelling and House Density (3, 4)
The average number of people living in each house or dwelling unit (BURBS) and the housing density,
the number of dwelling units per acre (BURBS) are part of the wastewater calculations in the BURBS
model. For the historic scenario, housing data was not available, so we assumed that there is are no
dwellings and no wastewater. For the existing scenario, there is 1 dwelling with 3 people that produces
300 gallons per day.
For the proposed and alternate scenarios, these values (items 3 and 4) were calculated based on the
expected gallons of wastewater generated per day. The number of dwellings was then back calculated
based on the assumption that there are 300 gallons/day/dwelling – (see Home Water Use per Person
(10)). For the alternative scenario, we expect 4,035 gallons per day. Given that there are 300
gallons/day/dwelling we would then have 13.45 dwellings (2 dwellings/acre). For the proposed scenario,
we expect 8,820 gallons per day, which means that there would be 29.4 dwellings at 300
gallons/day/dwelling (4.35 dwellings/acre). The average persons per dwelling, number of dwellings, and
housing density values therefore do not represent the actual circumstance, but rather are used to
ensure that it agrees with the expected gallons/day of wastewater produced.
Turf Fertilization Rate (13)
Average yearly nitrogen application rate expected from residential turf (BURBS). PWGC used 2.04
lbs/1000 sqft for the turf fertilization rate, which is the calculated rate according to the Long Island
Nitrogen Action Plans (LINAP) Nitrogen Loading Model (NLM) for residential application.
Fraction of Wastewater Nitrogen Lost as Gas (15)
Fraction of nitrogen in wastewater which volatilizes or is converted to gaseous nitrogen through
denitrification. Roughly 0.5 under Long Island, New York conditions (BURBS [5]). The proposed
development will utilize advanced onsite wastewater treatment systems. Based upon the nitrogen
removal efficiency of these systems of 85%, a value of 0.85 was used for the proposed development. For
the alternative plan a value of 0.5 was used since there will not be an advanced onsite wastewater
treatment system.
Summary of BURBS Model Results
As described above, PWGC utilized the BURBS model to estimate the nitrogen output from the four
scenarios: historic conditions, existing conditions, alternate plan and proposed development plan. The
BURBS model predicts nitrogen leached to groundwater independent of land area (i.e.: lbs
N/acre/year). In order to calculate the estimated mass of nitrogen leached to groundwater, the acreage
of each of the project components is multiplied by the model output, yielding pounds of nitrogen per
year. The total N leached and the N concentration in each scenario is summarized in Table 3, see below:
Table 3– BURBS Results Summary
56655 Route 25
Southold, NY
Sources of N Leached
Total N Leached N
Concentration Turf Natural
Land
Waste
Water
Impervious
Runoff
Scenario
lbs/acre/yr
lbs/acre/yr
lbs/acre/yr lbs/acre/yr
lbs/acre/yr lbs./yr mg/L
Historic
Conditions 22.98 0.10 2.57 0 25.66 173.28 3.30
Existing
Conditions 4.00 0.64 2.57 0.14 7.35 49.67 1.24
Alternate
Plan 9.84 0 34.58 4.99 49.41 333.74 4.55
Proposed
Development 15.24 0.02 22.68 3.35 41.30 278.91 3.28
The detailed model calculations are shown in Attachment A.
We expect the alternate scenario to have the highest total N leached, 333.74 lbs./year, and then
proposed scenario with 278.91 lbs./year (16% less). The existing scenario was calculated to leach 49.67
lbs./year and the historic scenario is was calculated to produce 173.28 lbs./year, mostly from farmland
(turf). The ranking of N concentration matches the ranking of N concentration, from highest to lowest:
alternate, proposed, historic, and existing.
Although the proposed scenario has more dwellings than the alternate (greater calculated wastewater
discharge) the fraction of wastewater N lost as gas is higher, so the N leached from wastewater is higher
in the alternate plan scenario. With more turf land in the proposed scenario, the N leached from turf is
higher than the alternate plan. The N leached from impervious runoff is comparable in the proposed and
alternate scenarios.
Resources
“Historical Aerials.” Suffolk County Government, www.suffolkcounty.gov/Deparatments/Economic-
Development-and-Planning/Planning-and-Environment/Cartography-and-GIS/Historical-Aerials
Suffolk County Water Authority (SCWA) 2018 Drinking Water Quality Report – Distribution Area 30, p.
45.
Attachment A – Detailed BURBS Model Calculations
"Enclaves"
Historic Conidtions
Welcome to BURBS
-----------------
A Lotus 1-2-3 spreadsheet for calculating the impact of residentia
development on the nitrate concentration in groundwater.
<<<< Center for Environmental Research, Cornell University >>>>
Ithaca, N.Y. 1985
There are 9 pages:
A B C D E F G H I J
1 +-----------------------------------------------+
Press the "Alt" š Welcome š Instructions š Definitions š
key with one š (you are here)š <Alt> I š (3 pages) š
letter 20 +---------------+---------------+ <Alt> D š
to switch š Parameters š Results š š
sections. š <Alt> P š <Alt> R š š
40 +---------------+---------------+ š
š Calculations š š š
Special š <Alt> C š š š
Commands: 60 +---------------+ +---------------+
<Alt> W = results + parameters on split screen š Bibliography š
<Alt> U = undo split screen <Alt> G = graphs +----<Alt> B----+
DATA - Enter a values for each parameter:
1. Fraction of land in turf 0.87 fraction
2. Fraction of land which is impervious 0.00 fraction
3. Average persons per dwelling 3.00 people
4. Housing density 0.15 dwellings/acre
5. Precipitation rate 47.00 inches/year
6. Water recharged from turf 35.25 inches/year
7. Water recharged from natural land 23.50 inches/year
8. Evaporation from impervious surface 0.10 fraction
9. Runoff from impervious recharged 1.00 fraction
10. Home water use per person 100.00 gallons/day
11. Nitrogen concentration in precip.0.71 mg/l
12. Nitrogen concentration in water used 5.18 mg/l
13. Turf fertilization rate 1.86 lbs/1000 sq ft
14. Fraction of nitrogen leached from turf 0.30 fraction
15. Fraction of wastewater N lost as gas 0.50 fraction
16. Wastewater fraction removed by Sewer 0.00 fraction
17. Nitrogen per person in wastewater 10.00 lbs/year
18. Nitrogen removal rate of natural land 0.90 fraction
INTERMEDIATE CALCULATIONS
Fraction Natural Land0.13
Population Density0.44people/acre
Nitrogen addition from precipitation7.57lbs/acre/year
N content of wastewater incl. water used11.58lbs/person/year
LABELS FOR GRAPH
Overall
TurfNitrate
NaturalConc. =
Sewage3.3
Runoff mg / liter
"Enclaves"
Historic Conidtions
INSTRUCTIONS
------------
It is assumed that you already know how to use Lotus 1-2-3.
This 1-2-3 spreadsheet is set up to calculate the amount of water and
nitrogen which will be recharged from a residential development.
It calculates loadings from wastewater, turf, natural land and runoff
from impervious surfaces.
You must enter values for all the parameters on the data page which
starts in cell A21. These parameters are defined and discussed on the
page to right of this one. ----->
If you are uncertain of the appropriate value to use for a
parameter, we suggest that you try several values in the range of
possible values. The numerical output from this model is only as
accurate as the parameters and assumptions and hence should be
interpreted carefully.
There are several predefined graphs which you can use.
This software is free to all owners of Lotus 1-2-3 and carries no
guarantee.
RESULTS:
WATER RECHARGED NITROGEN LEACHED
--------------- ----------------
inches/yrr percennt lbs/acre/yyr percent
--------- ------- ----------- -------
Turf30.589%23.090%
Natural Land3.29%0.10%
Wastewater0.62%2.610%
Impervious Runoff0.00%0.00%
TOTAL34.3 25.7
Nitrogen concentration in recharge3.30mg/l
Graphs of the data can be accessed by typing <Alt> G.
Select a graph, then type "Q" to exit graph menu.
"Enclaves"
Existing Conidtions
Welcome to BURBS
-----------------
A Lotus 1-2-3 spreadsheet for calculating the impact of residentia
development on the nitrate concentration in groundwater.
<<<< Center for Environmental Research, Cornell University >>>>
Ithaca, N.Y. 1985
There are 9 pages:
A B C D E F G H I J
1 +-----------------------------------------------+
Press the "Alt" š Welcome š Instructions š Definitions š
key with one š (you are here)š <Alt> I š (3 pages) š
letter 20 +---------------+---------------+ <Alt> D š
to switch š Parameters š Results š š
sections. š <Alt> P š <Alt> R š š
40 +---------------+---------------+ š
š Calculations š š š
Special š <Alt> C š š š
Commands: 60 +---------------+ +---------------+
<Alt> W = results + parameters on split screen š Bibliography š
<Alt> U = undo split screen <Alt> G = graphs +----<Alt> B----+
DATA - Enter a values for each parameter:
1. Fraction of land in turf 0.14 fraction
2. Fraction of land which is impervious 0.02 fraction
3. Average persons per dwelling 3.00 people
4. Housing density 0.15 dwellings/acre
5. Precipitation rate 47.00 inches/year
6. Water recharged from turf 35.25 inches/year
7. Water recharged from natural land 23.50 inches/year
8. Evaporation from impervious surface 0.10 fraction
9. Runoff from impervious recharged 1.00 fraction
10. Home water use per person 100.00 gallons/day
11. Nitrogen concentration in precip.0.71 mg/l
12. Nitrogen concentration in water used 5.18 mg/l
13. Turf fertilization rate 2.04 lbs/1000 sq ft
14. Fraction of nitrogen leached from turf 0.30 fraction
15. Fraction of wastewater N lost as gas 0.50 fraction
16. Wastewater fraction removed by Sewer 0.00 fraction
17. Nitrogen per person in wastewater 10.00 lbs/year
18. Nitrogen removal rate of natural land 0.90 fraction
INTERMEDIATE CALCULATIONS
Fraction Natural Land0.84
Population Density0.44people/acre
Nitrogen addition from precipitation7.57lbs/acre/year
N content of wastewater incl. water used11.58lbs/person/year
LABELS FOR GRAPH
Overall
TurfNitrate
NaturalConc. =
Sewage1.2
Runoff mg / liter
"Enclaves"
Existing Conidtions
INSTRUCTIONS
------------
It is assumed that you already know how to use Lotus 1-2-3.
This 1-2-3 spreadsheet is set up to calculate the amount of water and
nitrogen which will be recharged from a residential development.
It calculates loadings from wastewater, turf, natural land and runoff
from impervious surfaces.
You must enter values for all the parameters on the data page which
starts in cell A21. These parameters are defined and discussed on the
page to right of this one. ----->
If you are uncertain of the appropriate value to use for a
parameter, we suggest that you try several values in the range of
possible values. The numerical output from this model is only as
accurate as the parameters and assumptions and hence should be
interpreted carefully.
There are several predefined graphs which you can use.
This software is free to all owners of Lotus 1-2-3 and carries no
guarantee.
RESULTS:
WATER RECHARGED NITROGEN LEACHED
--------------- ----------------
inches/yrr percennt lbs/acre/yyr percent
--------- ------- ----------- -------
Turf4.919%4.054%
Natural Land19.876%0.69%
Wastewater0.62%2.635%
Impervious Runoff0.83%0.12%
TOTAL26.1 7.4
Nitrogen concentration in recharge1.24mg/l
Graphs of the data can be accessed by typing <Alt> G.
Select a graph, then type "Q" to exit graph menu.
"Enclaves"
Alternate Plan
Welcome to BURBS
-----------------
A Lotus 1-2-3 spreadsheet for calculating the impact of residentia
development on the nitrate concentration in groundwater.
<<<< Center for Environmental Research, Cornell University >>>>
Ithaca, N.Y. 1985
There are 9 pages:
A B C D E F G H I J
1 +-----------------------------------------------+
Press the "Alt" š Welcome š Instructions š Definitions š
key with one š (you are here)š <Alt> I š (3 pages) š
letter 20 +---------------+---------------+ <Alt> D š
to switch š Parameters š Results š š
sections. š <Alt> P š <Alt> R š š
40 +---------------+---------------+ š
š Calculations š š š
Special š <Alt> C š š š
Commands: 60 +---------------+ +---------------+
<Alt> W = results + parameters on split screen š Bibliography š
<Alt> U = undo split screen <Alt> G = graphs +----<Alt> B----+
DATA - Enter a values for each parameter:
1. Fraction of land in turf 0.34 fraction
2. Fraction of land which is impervious 0.66 fraction
3. Average persons per dwelling 3.00 people
4. Housing density 1.99 dwellings/acre
5. Precipitation rate 47.00 inches/year
6. Water recharged from turf 35.25 inches/year
7. Water recharged from natural land 23.50 inches/year
8. Evaporation from impervious surface 0.10 fraction
9. Runoff from impervious recharged 1.00 fraction
10. Home water use per person 100.00 gallons/day
11. Nitrogen concentration in precip.0.71 mg/l
12. Nitrogen concentration in water used 5.18 mg/l
13. Turf fertilization rate 2.04 lbs/1000 sq ft
14. Fraction of nitrogen leached from turf 0.30 fraction
15. Fraction of wastewater N lost as gas 0.50 fraction
16. Wastewater fraction removed by Sewer 0.00 fraction
17. Nitrogen per person in wastewater 10.00 lbs/year
18. Nitrogen removal rate of natural land 0.90 fraction
INTERMEDIATE CALCULATIONS
Fraction Natural Land0.00
Population Density5.97people/acre
Nitrogen addition from precipitation7.57lbs/acre/year
N content of wastewater incl. water used11.58lbs/person/year
LABELS FOR GRAPH
Overall
TurfNitrate
NaturalConc. =
Sewage4.5
Runoff mg / liter
"Enclaves"
Alternate Plan
INSTRUCTIONS
------------
It is assumed that you already know how to use Lotus 1-2-3.
This 1-2-3 spreadsheet is set up to calculate the amount of water and
nitrogen which will be recharged from a residential development.
It calculates loadings from wastewater, turf, natural land and runoff
from impervious surfaces.
You must enter values for all the parameters on the data page which
starts in cell A21. These parameters are defined and discussed on the
page to right of this one. ----->
If you are uncertain of the appropriate value to use for a
parameter, we suggest that you try several values in the range of
possible values. The numerical output from this model is only as
accurate as the parameters and assumptions and hence should be
interpreted carefully.
There are several predefined graphs which you can use.
This software is free to all owners of Lotus 1-2-3 and carries no
guarantee.
RESULTS:
WATER RECHARGED NITROGEN LEACHED
--------------- ----------------
inches/yrr percennt lbs/acre/yyr percent
--------- ------- ----------- -------
Turf12.025%9.820%
Natural Land0.00%0.00%
Wastewater8.017%34.670%
Impervious Runoff27.958%5.010%
TOTAL47.9 49.4
Nitrogen concentration in recharge4.5mg/l
Graphs of the data can be accessed by typing <Alt> G.
Select a graph, then type "Q" to exit graph menu.
"Enclaves"
Proposed Development
Welcome to BURBS
-----------------
A Lotus 1-2-3 spreadsheet for calculating the impact of residentia
development on the nitrate concentration in groundwater.
<<<< Center for Environmental Research, Cornell University >>>>
Ithaca, N.Y. 1985
There are 9 pages:
A B C D E F G H I J
1 +-----------------------------------------------+
Press the "Alt" š Welcome š Instructions š Definitions š
key with one š (you are here)š <Alt> I š (3 pages) š
letter 20 +---------------+---------------+ <Alt> D š
to switch š Parameters š Results š š
sections. š <Alt> P š <Alt> R š š
40 +---------------+---------------+ š
š Calculations š š š
Special š <Alt> C š š š
Commands: 60 +---------------+ +---------------+
<Alt> W = results + parameters on split screen š Bibliography š
<Alt> U = undo split screen <Alt> G = graphs +----<Alt> B----+
DATA - Enter a values for each parameter:
1. Fraction of land in turf 0.53 fraction
2. Fraction of land which is impervious 0.44 fraction
3. Average persons per dwelling 3.00 people
4. Housing density 4.35 dwellings/acre
5. Precipitation rate 47.00 inches/year
6. Water recharged from turf 35.25 inches/year
7. Water recharged from natural land 23.50 inches/year
8. Evaporation from impervious surface 0.10 fraction
9. Runoff from impervious recharged 1.00 fraction
10. Home water use per person 100.00 gallons/day
11. Nitrogen concentration in precip.0.71 mg/l
12. Nitrogen concentration in water used 5.18 mg/l
13. Turf fertilization rate 2.04 lbs/1000 sq ft
14. Fraction of nitrogen leached from turf 0.30 fraction
15. Fraction of wastewater N lost as gas 0.85 fraction
16. Wastewater fraction removed by Sewer 0.00 fraction
17. Nitrogen per person in wastewater 10.00 lbs/year
18. Nitrogen removal rate of natural land 0.90 fraction
INTERMEDIATE CALCULATIONS
Fraction Natural Land0.03
Population Density13.06people/acre
Nitrogen addition from precipitation7.57lbs/acre/year
N content of wastewater incl. water used11.58lbs/person/year
LABELS FOR GRAPH
Overall
TurfNitrate
NaturalConc. =
Sewage3.3
Runoff mg / liter
"Enclaves"
Proposed Development
INSTRUCTIONS
------------
It is assumed that you already know how to use Lotus 1-2-3.
This 1-2-3 spreadsheet is set up to calculate the amount of water and
nitrogen which will be recharged from a residential development.
It calculates loadings from wastewater, turf, natural land and runoff
from impervious surfaces.
You must enter values for all the parameters on the data page which
starts in cell A21. These parameters are defined and discussed on the
page to right of this one. ----->
If you are uncertain of the appropriate value to use for a
parameter, we suggest that you try several values in the range of
possible values. The numerical output from this model is only as
accurate as the parameters and assumptions and hence should be
interpreted carefully.
There are several predefined graphs which you can use.
This software is free to all owners of Lotus 1-2-3 and carries no
guarantee.
RESULTS:
WATER RECHARGED NITROGEN LEACHED
--------------- ----------------
inches/yrr percennt lbs/acre/yyr percent
--------- ------- ----------- -------
Turf18.633%15.237%
Natural Land0.71%0.00%
Wastewater17.632%22.755%
Impervious Runoff18.734%3.48%
TOTAL55.6 41.3
Nitrogen concentration in recharge3.3mg/l
Graphs of the data can be accessed by typing <Alt> G.
Select a graph, then type "Q" to exit graph menu.
"Enclaves"
Parameter Definitions
---------------------
1.Fraction of land in turf - refers to area maintaned as lawn,
must be between 0 and 1.
2.Fraction of land which is impervious - sum of roof area, driveways
and roads; must be between 0 and 1. The fraction of land in natural
vegetation is computed as 1 minus the sum of fraction in turf and
the fraction impervious, thus the sum of these 2 must be less than 1.
3.Average persons per dwelling - the average number of people living in
each house or dwelling unit.
4.Housing density - the number of dwelling units per acre.
5.Precipitation rate - the annual average precipitation in inches.
6.Water recharged from turf - the amount of water per unit area of turf
which drains to groundwater. This can be computed from a water budget
for the root zone. A 1-2-3 spreadsheet is available for this. [1]
7.Water recharged from natural land - the amount of water per unit area
of natural of natural vegetation which drains to groundwater. This
can be computed from a water budget.
8.Evaporation from impervious surface - the fraction of precipitation
falling on impervious surface assumed to evaporate. Try 0.10. [1]
9.Runoff from impervious recharged - The fraction of the runoff which
is recharged through recharge basins, ponds etc. Evaporation is
subtracted. Use 0 here if storm sewers drain all runoff to surface
waters.
10.Water use per person - average in-home use of water. Try 44 gallons
per person per day. [2]
11.Nitrogen concentration in precipitation - average concentration,
Use data from closest weather station where nitrogen tests were
done.
12.Nitrogen concentration in water used - average concentration in
water used in homes.
13.Turf fertilization rate - average yearly nitrogen application rate
expected for residential turf.
14.Fraction of nitrogen leached from turf - the fraction of nitrogen
applied from fertilizer, precipitation etc. which leaches to
groundwater. For sandy soil try 0.35 if clippings are removed, or
try 0.5 if clippings are left on turf. These values are based on
Long Island studies [3],[4]. For tighter soils the fraction leached
will probably be less.
15.Fraction of Wastewater N lost as gas - fraction of nitrogen in
wastewater which volatilizes or is converted to gaseous N through
denitrification. Roughly 0.50 under Long Island, N.Y. conditions.[5]
This value is dependent on temperature and soil. Warmer areas will
probably have higher fractions volatilized as will areas with
tighter soils. Colder areas will probably have lower fractions.
Vary this widely in your sensitivity analysis. (Perhaps 0.2 to 0.8)
16.Fraction of wastewater removed by sewer - efficiency of sewer. Try
0.90 which is to assume that 10% exfiltrates from sewers. If no
sewers are present use 0. [4]
17.Nitrogen per person in wastewater - the average in the U.S. is
10 lbs/person/day. [2]
18.Nitrogen removal rate of natural land - the fraction of nitrogen in
precipitation which is removed by natural land before the water is
recharged. Should be at least 90 percent. Try 95 percent for
forested areas.
"Enclaves"
BIBLIOGRAPHY
------------
[1]Mather, John R. 1979. The Influence of Land-Use Change on Water
Resources. Water Resources Center, University of Delaware. Newark,
Delaware.
[2]Long Island Regional Planning Board. 1978. Long Island Comprehensive
Waste Treatment Management Plan (208 study). Hauppauge, N.Y.
[3]Hughes, Henry B.F. and K.S. Porter. 1983. Land Use and Ground Water
Quality in the Pine Barrens of Southampton. Center for Environmental
Research, Cornell University, Ithaca, N.Y.
[4]Hughes, Henry B.F., J. Pike and K.S. Porter. 1985. Assessment of
Ground-Water Contamination by Nitrogen and Synthetic Organics in Two
Water Districts in Nassau County, N.Y. Center for Environmental
Research, Cornell University, Ithaca, N.Y.
[5]Andreoli, A., R. Reynolds, N. Bartilucci and R. Forgione. 1977.
Pilot Plant Study: Nitrogen Removal in a Modified Residential
Subsurface Disposal System. Suffolk County Department of Health
Services, Hauppauge, N.Y.