5th issue 2026 kt #2

Land use

human use of land, represents the economic and cultural activities practiced in a given place.

What can land use changes effect?

air and water quality, watershed function, generation of waste, extent and quality of wildlife habitat, climate, and human health

Why is the EPA concerned about different land use activities?

Because of their potential effects on the environement and human health

2 primary areas of concern by the epa for land use

land development and agricultural uses

how do impervious surfaces contribute to nps pollution?

by limiting the capacity of soils to filter runoff

Other impervious surfaces effects

affects peak flow and water volume and heighten erosion potential, increase storm water runoff, and affect groundwater aquifer recharge

Point source discharges

From industrial and municipal wastewater treatment facilities can contribute toxic compounds and heated water

ROE

EPA’s Report on Environment

Effects of land development patterns

Increase air pollution due to vehicle uses - higher concentrations of certain air pollutants

Can lead to heat islands

heat islands

domes of warmer air over urban and suburban areas that are caused by the loss of trees and shrubs and the absorption of mroe heat by pavement, buildings, and other sources.

Agricultural land uses and water/watershed quality

types of crops planted, tillage practices, and various irrigation practices can limit the amount of water available for other uses, livestock grazing in riparian zones can change landscape conditions, runoff from pesticides, fertilizers, and nutrients from animal manure, loss of native habitats, spread of invasive species

Limitations of available indicators for trends about land use trends

lack of data, varying approaches to data classification and measurement, and difficulty in delineating land use.

What everyday driving habit contributes meaningfully to atmospheric nitrogen deposition int he Chesapeake Bay airshed?

Combustion of gasoline and diesel produces nitrogen oxides (NO), which return to land and water as wet or dry atmospheric deposition. The Bay airshed is around 570,000 square miles so emissions from Ohio, PA, VA, and beyond reach the Bay. Reducing vehicle miles (carpooling, transit, biking, walking) and choosing electric vehicles reduces this load.

A footprint calculator tells a Bethesda student their water footprint is 2,100 gallons per day. National average is around 2000. Why might that seem high for an individual whose direct water use is only around 80 gallons per day?

A person’s direct use of water is only a small fraction (around 5%) of their overall water footprint. Most water consumption comes from the clothing industry, food, electronics, energy, and other goods the student consumes, far from the household tap.

A high school student wants to reduce their personal NPS pollution footprint. Rank these four actions by likely impact, highest to lowest: a) switching to a plant-based diet, b) carpooling to school, c) using a reusable water bottle, d) shortening showers by 2 minutes

a) huge virtual water and nutrient runoff reduction. b) cuts NO emissions to the airshed, d) cuts blue water use and wastewater, c) small but real. All are worthwhile, diet usually dominates

If your personal water footprint includes the water used to grow soybeans for animal feed in Iowa, what NPS pollution problem in the Gulf of Mexico are you partly contributing to?

Dead zones. Soybean and corn farming in the Mississippi River basin is a primary source of the nitrogen and phosphorus runoff that creates the Gulf of Mexico hypoxic “dead zone”. Consumer demands for meat and animal feed sustains that agricultural footprint.

How does illustrating personal footprint connect KT2 (individual contribution to NPS) to KT3 (community action) in the Envirothon curriculum?

A personal footprint shows what one student does. Multiplied by 18.9 Bay residents, those individual contributions become the aggregate sources tracked at watershed scale. Community based solutions (KT3) bridge the gap: collective actions scale individual changes into measurable load reductions. The footprint is the unit; the community is the multiplier.

A coffee shop in Annapolis uses single-use plastic cups, lids, and stirrers. How does this contribute to NPS pollution in the Severn River?

Plastic litter from the shop and its customers gets dropped on streets and sidewalks, washes into storm drains during rain events, and enters tributaries. Plastic fragments into microplastics over time, which are now detected throughout Bay waters. Baltimore Inner Harbor’s Mt. Trash Wheel family ahs collected 1,608 tons of trash, with chip bags, plastic bottles, and polystyrene among the highest-volume categories.

How does a footprint calculator work and what is it used to teach?

A footprint calculator asks the user about diet, transportation, energy use, and consumption habits, then estimates the user’s annual water, carbon or ecological footprint by multiplying each input by published impact factors. It is used to make abstract environmental impacts personal and tangible - showing where a single person’s biggest leverage points actually are, often surprising users.

What is the EcoRise Water Footprint Calculator, and what is its educational purpose?

EcoRise offers an online water footprint calculator designed for classroom and individual use. It walks students through diet, transportation, indoor and outdoor water use, and consumption patterns to estimate their gallons-per-day footprint. The educational purpose is to convert abstract national water statistics into a personal number students can compare and act on.

Define water footprint and the three categories that make it up.

A water footprint is an assessment of water use that includes both direct use (wat you drink, bathe, water lawns with) and virtual water (water embedded in the goods and services you consume). The three categories are: Blue (surface and groundwater consumed), green (rainwater consumed), and grey (water needed to dilute the wastewater generated).

A family of four in suburban MD wants to cut their household water footprint by 25%. Where should they look first, and why?

Diet (especially red meat and dairy) usually offers the largest reductions because virtual water in food dominates household footprints. Lawn irrigation is the next-largest single residential use in warm months. Indoor water (showers, toilets, dishwashers) is third. Direct conservation of indoor water alone rarely reaches 25%; meaningful cuts typically require dietary changes plus efficient outdoor practices.

How can illustrating a personal NPS footprint be more motivating than describing watershed-level statistics?

Watershed statistics are abstract and feel beyond individual influence. A personal footprint locates the student inside the system - showing their specific contribution and the specific actions that would reduce it. This shifts the narrative from “someone else’s problem” to “my contribution, my leverage”.

Compare the blue, green, and grey water footprints by what each measures.

Blue water: surface water and groundwater consumed (evaporated or incorporated) to produce a good> Green water: rainwater consumed (evaporated or used directly) to produce a good. Grey water: freshwater required to dilute wastewater generated by production to meet water quality standards. Together they give a fuller accounting of water embedded in goods than direct use alone.

How can the simple act of washing a car at home contribute to NPS pollution and what is the alternative?

Washing a car in a driveway releases soaps, oils, grease, brake dust, and road grime directly into storm drains, which discharge untreated to streams. Commercial car washers are required to drain to sanitary sewers, where wastewater is treated. Alternatively washing on grass allows infiltration and biological infiltration before runoff reaches a stream.

List 5 categories of household chemical that should never be poured down storm drains or into the ground.

Motor oil, antifreeze, and other automotive fluids; paint, paint thinner, and solvents; pesticides and herbicides; pharmaceuticals; and household cleaners with bleach or ammonia. All should be taken to designated household hazardous waste collection.

Compare the long-term forest-loss rates between the agricultural era (18th-19th centuries) and the modern development era (1982-present) in the Bay watershed.

Agricultural era: 70-80% of the watershed’s original forest cover was removed by the late 1800s for firewood, fencing, and farmland. Modern era: forest is being lost again but to development - around 100 acres/day form 1982-1997, around 70 acres/day by 2006. The composition ahs also homogenized - modern “new” forests are more uniform in age, size, and species than the original pre-colonial forests.

Why is pet waste an NPS concern in residential Maryland neighborhoods, beyond being a nuisance?

Pet waste contains nitrogen, phosphorus, and pathogenic bacteria (E.coli, Giardia, Salmonella). When it’s left on lawns or sidewalks, rain washes the nutrients and pathogens into storm drains and directly into local creeks. A single average dog produces enough waste in a year to contaminate a substantial volume of receiving water. Bacterial loading from pet waste is a leading cause of summer beach closures.

Why does using a gas-powered leaf blower contribute to NPS pollution in the Bay watershed?

Small two-stroke engines emit disproportionately high air pollutants - NO, particulates, hydrocarbons - relative to their size. NO returns tot he watershed as nitrogen via atmospheric deposition (around 6% of Bay nitrogen comes from atmospheric deposition per 2024 modeling, with vehicles and small engines as major contributors). Switching to electric or manual tools is one of the at-home actions CBP recommends.

List 5 common consumer products or partices that contribute to NPS pollution through indirect pathways

Lawn fertilizer (N and P runoff), pesticides and herbicides (toxic runoff), motor oil (improper disposal or leaks), car washing on driveways (soaps, road grime to storm drains), pet waste left on lawns, household chemicals improperly disposed, gas-powered lawn equipment (air-pollution to atmospheric deposition), and prescription medications flushed down toilets (pharmaceuticals in wastewater)

A homeowner applies lawn fertilizer right before a forecasted rainstrom to “water it in”. Why does this practice maximize NPS pollution rather than fertilization?

Plants need time to contact with soil to absorb fertilizer. Rain immediately after application washes most of the unincorporated nutrients into storm drains and streams before grass roots can take them up. Best practice is to apply when no significant rain is forecast for 48-72 hours and water lightly only if the lawn is dry.

WHy is teh application of de-icing salt to driveways and sidewalks an NPS pollution concern

Road salt (sodium chloride and calcium chloride) dissolves in snowmelt and runoff and carries directly to streams. Chloride concentrations in urbanized Bay tributaries have risen markedly over decades. High chloride is toxic to freshwater aquatic life, alters soil chemistry, and corrodes infrastructure. Urban watersheds show the highest chloride concentrations in regional studies.

What is the most water-intensive everyday consumer product among these: a pair of jeans, a smartphone, a pound of beef, or a paper book? Provide the approximate virtual water cost of each.

Pound of beef - 1581, pair of jeans - 2866 gallons, smartphone - 3190 gallons (highest). Paper book: a few hundred gallons. The smartphone is highest because of the water-intensive electronics supply chain - mining, refining, semiconductor fabrication.

Why are pharmaceuticals and emerging NPS pollution concern in Maryland waterways?

Pharmaceuticals enter wastewater through human excretion and improper disposal (flushing). Conventional wastewater treatment does not remove them effectively. They are detected at low concentrations in Bay tributaries and have been linked to endocrine disruption in fish - including intersex characteristics in smallmouth bass in the Potomac watershed.

A residential property has bare-soil areas where grass won’t grow. What NPS pollution category is this likely producing during rainstorms?

Sediment runoff. Bare residential soil erodes during rain events, carrying sediment plus any attached pollutants (residual fertilizer, pesticides) to storm drains. Remedies include planting groundcover, mulching, or installing rain gardens. Bare soil erosion is one of the most overlooked residential NPS sources.

How does climate change interact with population growth to worsen NPS pollution in Maryland.

Climate change is bringing more intense precipitation to the Mid-Atlantic - the Northeast saw a 70%+ increase in heavy precipitation events between 1958 and 2012, the largest of any US region. Intense rain on a watershed already laden with impervious cover from population growth generates flashier, larger runoff events that scour streambanks, overwhelm aging wastewater systems, and deliver large pollutant pulses to the Bay.

Compare nitrogen and phosphorus contributions to the Bay from agriculture versus wastewater (2024 CBP figures)

Agriculture: 46% N, 29% P. Wastewater (not including septic) 11% N, 16% P. Agriculture is roughly 4x higher for N and 1.8x higher for P. Wastewaters share has declined sharply since 1985 (57% N reduction, 75% P reduction) due to BNR/ENR upgrades; agriculture’s share has been slower to decline

A schoolyard, a family farm, and a residential street are each considering the same BMP question - how to reduce runoff. What different BMP fits each context?

Schoolyard: bioretention/rain garden, permeable pavement in parking areas, green roof on the building. Family farm: cover crops to keep soil covered in winter, riparian forest buffer along the stream, livestock stream-exclusion fencing. Residential street: rain barrels: redirected downspouts to vegetated areas, narrowed streets with curb cuts to bioswales.

Compare runoff volume from a typical city block versus a forested area of the same size, according to EPA estimates.

A typical city block generates more than 5x the runoff of a forested area of equal size. Forests intercept rainfall in canopy, allow infiltration, and slow surface flow; pavement and rooftops do none of those things.

A thousand acre forest, a thousand acre row-crop farm, and a thousand acre suburban subdivision sit side by side. Rank them by typical annual stormwater volume generated, lowest to highest.

Forest (lowest - high infiltration, canopy interception, dense root systems), row-crop farm (middle - moderate infiltration, seasonal bare soil after harvest), suburban subdivision (highest - 30-50% impervious cover plus compacted lawn soils that resist infiltration). The suburban site can generate 5x+ more runoff than the forest.

Compare the pollutant-loading impacts of urban runoff versus agricultural runoff at the per-acre level in Maryland

Per-acre, agricultural land typically delivers more total nutrients (especially nitrate and phosphorus) than urban land. But because urban land has much higher runoff volume per acre and concentrates many people’s pollution sources, the per-acre impact on stream chemistry (turbidity, bacterial loading, peak flows, heavy metals) is often more acute. In Bay-wide aggregate, agriculture remains the larger contributor of N and P; stormwater is the fastest-growing contributor.

Compare the lag time between BMP adoption and water-quality improvement for an urban rain garden versus a farm cover crop in an Eastern Shore tile-drained field.

Urban rain garden: response is fast - captured runoff is treated immediately and improvements show within one storm season. Eastern Shore cover crop: response is delayed by groundwater lag, because much of the nitrogen reaches streams through subsurface flow. On the Delmarva Peninsula, groundwater nitrate takes 20-40 years to reach surface waters, so today’s cover-crop benefits will not be fully visible in stream chemistry for decades.

Compare the per-acre sediment loading from a Typical agricultural field versus a typical active construction site.

Construction sites produce roughly 10 to 20 times more sediment per acre than agricultural lands. Exposed, disturbed, and unvegetated soil during the construction phase is the most erodible land cover of any land use.

Compare how nitrogen reaches a stream from an urban lawn versus from a row-crop cornfield in Maryland

Urban lawn: applied N runs off the surface during rain into storm drains, OR leaches into shallow groundwater and seeps to streams. Compacted suburban soils favor mroe surface runoff. Cornfield: applied N partially uptakes into the crop, partially volatilizes, partially runs off surface, and significantly leaches through tile drains and into groundwater (with 20-40 year lag time on Delmarva). The cornfield generally delivers more total N per acre per year.

Compare the dominant pollutant signature of a heavily urbanized watershed versus a heavily agricultural watershed

Urban: highest chloride concentrations form road salt; significant heavy metals, hydrocarbons (oil/grease), bacterial loading (pet waste, septic failures); sediment form construction. Agricultural: highest nitrate-N concentrations; phosphorus loading correlated with tile drainage and manure application; pesticides; sediment from cultivated fields and streambank erosion.

compare the typical responses of “flashy” urbanized streams versus forested streams to a 2-inch rain event

Urbanized stream: rapid peak discharge (short lag time), high peak flow, brief duration, severe erosive force on banks, abrupt sediment and pollutant pulse, fast return to low flow. Forested stream: delayed peak (long lag time), lower peak flow, longer duration, sustained moderate flow, much smaller pollutant pulse, slow tail of base flow contribution from groundwater.

compare the role of impervious surface percentage in urban versus rural watersheds for predicting stream degradation

Even in mostly rural watersheds, impervious surface above 10% of total area is associated with measurable stream degradation. In urban watersheds where impervious cover exceeds 25-30%, degradation is severe. The 10% threshold is consistent across land use types, making impervious cover a powerful single predicator of stream health.

How does population growth in the Chesapeake watershed translate into NPS pollution increases, mechanistically?

Growth drives land conversion: forests and farms are replaced with roads, rooftops, lawns, and parking lots. Impervious cover rises, runoff volume and speed increase, and natural filtration is lost. Wastewater volume rises, overwhelming older treatment systems during storms. The personal footprint of each resident (driving, fertilizing, heating) also adds emissions and loads.

What does “agricultural intensification” mean, and how does it contribute to NPS pollution beyond simple farm expansion

Agricultural intensification is the increase in production per acre - more fertilizer, more pesticides, more irrigation, higher livestock densities - on the same or shrinking footprint. As urban growth consumes farmland, remaining farms are pushed into intensify to maintain output, which raises nutrient and chemical laoding per acre even when total farmed acreage declines.

What is the “heat island” effect, and how does it amplify NPS-related water quality problems?

Dense urban areas with high impervious cover and little vegetation absorb and retain heat, making them several degrees warmer than surrounding rural areas. Hotter pavement heats stormwater before it reaches streams, raising stream temperatures and reducing dissolved oxygen. Warmer cities also drive higher air pollution (more ozone formation), more energy use (more emissions), and more water demand.

How many people live int he Chesapeake Bay watershed today, and how has that changed since 1950?

Approximately 18.9 million people (2024). The watershed population has more than doubled since 1950 and is projected to exceed 20 million by 2040, reaching around 21.7 million by 2050.

How much forest has the Chesapeake Bay watershed lost to development, and at what historic rate?

Between 1982 and 1997, the watershed lost more than 750,000 acres of forest - roughly 100 acres per day. By 2006 the rate had fallen to about 70 acres/day, still considered unsustainable. The watershed has lost around 100,000 acres of natural forests to developed lands in recent years.

How does poultry production specifically on MD’s eastern shore intensify the nutrient pollution challenge compared to row-crop farming alone?

Poutlry houses concentrate large numbers of birds in small areas, producing manure (poultry litter) far in excess of what local cropland can absorb. Excess litter often exceeds the receiving fields’ nutrient requirements, leading to over-application. Ammonia volatilizes into the air (returning later as atmospheric deposition), and runoff carries N and P to tributaries. The high phosphorus saturation of Eastern Shore soils from decades of litter application is a persistent NPS legacy.

Between 1990 and 2007, watershed population grew by 18% but impervious surface from single-family homes grew by what percentage? what does this gap reveal?

Impervious surfaces from single-family homes grew approximately 34%, roughly double the population growth rate. This reveals that the per-person environmental footprint is growing - newer development uses more land per resident than older patterns did (larger lots, more pavement, more roads per household).

In a Maryland Piedmont county like Montgomery or Howard, what happens to the NPS pollution profile as farmland is converted to suburban housing developments?

The pollution mix shifts but total loads often rise. Sediment loads spike during the construction phase (construction sites produce 10-20x more sediment per acre than ag land). Long-term, agricultural nitrogen and pesticide inputs are replaced by lawn fertilizer, pet waste, road salt, vehicle fluids, and pharmaceuticals in wastewater. Impervious cover increases, so runoff volume and flashiness rise sharply.

How is the increasing global demand for water connected to the concept of NPS pollution?

Rising water demand is driven by population growth and intensifying use of water-intensive goods. Experts project global water demand will exceed supply by 40% by 2030. Strained water resources mean less dilution capacity for pollutants and more pressure to use marginal-quality water, both of which amplify the impacts of NPS pollution that already enters the system.

what is “sprawl” and why is it more damaging to water quality than denser urban development?

Sprawl is land development built away from existing town centers, creating low-density residential and commercial areas filled in with new infrastructure (roads, schools, shopping). It consumes more land per resident than dense development, replaces more forests and wetlands with impervious surfaces, and requires more vehicle travel - multiplying the NPS pollution per capita.

why does the “southern ontario land cover study” suggest about a threshold for nitrogen contamination in agricultural watersheds, and why is it relevant to Maryland?

Nitrate-N concentrations in streams increased dramatically once row crop cover exceeded approximately 30% of the watershed. Below that threshold, riparian buffers, forests, and wetlands absorbed the nitrogen load; above it, the landscape’s assimilation capacity was overwhelmed. Relevant to Maryland because many Eastern Shore subwatersheds substantially exceed 30% row crop cover.

What is “virtual water” and how does it connect everyday consumer choices to global NPS pollution?

Virtual water is the water embedded in producing a good - the water consumed and polluted along the supply chain. EX: 1 pound of beef around 1,581 gallons; one pair of jeans around 2,866 gallons; a smartphone around 3,190 gallons. Consumer demand for water-intensive products drives agriculture, manufacturing, and energy systems that generate NPS pollution far form the point of consumption.

how can faulty septic systems in rural MD counties contribute to NPS pollution even it visually nothing appears wrong?

Failing septic drainfields release partially treated sewage into shallow groundwater that discharges to nearby streams. Indicators are usually invisible - there’s no surface effluent - but nitrogen, phosphorus, and bacteria leach steadily. Maryland recommends septic pumping and inspection every 3-5 years. Failed septics are a significant NPS contributor in rural Charles, St. Mary’s, and Anne Arundel counties.

Why does the food a person eats account for the largest part of their personal water and NPS footprint?

Food production - especially animal protein, irrigated crops, and processed foods - is the most water - and nutrient-intensive sector of the economy. A single pound of beef requires around 1.581 gallons of virtual water plus generates substantial manure-related nutrient runoff. Plant-based foods generally require far less. Food choices therefore have larger water and NPS footprints than most household activities combined

How does the concept of a personal water footprint help connect a Maryland student to NPS pollution in distant watersheds - like the Colorado River Basin?

When the student buys clothing made from cotton grown in irrigated California or Arizona fields, or eats beef from feedlots in the Midwest, the virtual water they consume comes form those distant watersheds. The fertilizer and pesticide NPS pollution those farms generate is partly driven by the student’s demand. The footprint concept makes that invisible connection visible.