80%
of buyers now consider environmental risk when purchasing
Zillow, 2024
72%
say risks should be disclosed — almost none are required to be
LendingTree, 2024
48%
of buyers who knew about risks still experienced weather-related damage
Insurify, 2025
#1
US county by numeric population growth — 48,695 new residents in 2024–25
US Census, 2025
Harris County is America's fastest-growing county — and that growth comes with environmental and safety tradeoffs that rarely appear in a home search. Your realtor knows what comparable homes sold for. Your inspector knows whether the roof leaks. EarthScore360 covers the county-level risks neither of them are required to tell you: air quality, drinking water contaminants, flood zone exposure, crime trends, and more — all sourced from EPA, FEMA, FBI, and US Census data.
In November 2025, Zillow removed environmental risk scores from 135 million listings after real estate industry pressure.
EarthScore360 is independent — we answer to homebuyers, not sellers or agents.
Risk scores by category
7 domains · EPA, FEMA, TCEQ dataAir Quality
38
Serious Ozone Nonattainment + PM2.5 Nonattainment. Worst air quality in Texas. Ship Channel industrial corridor the primary source. Northwest suburbs score significantly better.
Climate Hazard
32
1 in 4 properties in a FEMA floodplain. Harvey (2017) flooded 154,000 structures — the costliest US flood event ever. MAAPnext maps expanding floodplain ~33% in 2026.
Urbanization
48
Impervious surface exceeds 40% in the urban core, intensifying flooding, urban heat, and green space loss. Adding ~49K residents/yr puts extreme infrastructure pressure on a county with no zoning.
Env. Justice
45
68th percentile EJI burden nationally. Lower-income communities concentrated along the Ship Channel and I-10 East bear disproportionate industrial pollution exposure with no structural improvement trend.
Community Safety
58
Violent crime rate of ~420 per 100K — above the Texas average of 395. Significant variation: west and northwest suburbs score well above average while eastern corridors are elevated.
Water Resources
63
Meets current standards but multiple contaminants of concern: PFAS from Ship Channel corridor, arsenic in Gulf Coast Aquifer, nitrates from agricultural runoff, disinfection byproducts (TTHMs/HAA5s), and 1,4-dioxane from industrial sources. Flood contamination risk extreme — Harvey 2017 impacted 154K structures.
PFAS
Monitoring ongoing
Ship Channel corridor elevated
Arsenic
Detected
Naturally occurring in aquifer
Nitrates
Above average
Agricultural runoff, outer MUDs
DBPs (TTHMs)
Present
Chlorination byproducts
1,4-Dioxane
Industrial sources
Emerging contaminant
Lead risk
Pre-1986 homes
Lead solder in older pipes
Compliance
Generally passing
Current EPA standards met
Flood contam.
High risk
Harvey 2017: 154K structures
Ecosystem Health
68
Armand Bayou Nature Center, Galveston Bay, and Buffalo Bayou Park provide ecological anchors. Tree canopy declined 9.9% from 2011–2021. Bayou prairie restoration projects underway.
What homebuyers need to know
Key findings🌊 Flood risk
FEMA is redrawing flood maps in 2026. Many properties currently outside flood zones will be reclassified under MAAPnext. Harvey (2017) flooded 154,000 structures causing $125B damage — the costliest US flood event ever. Always verify your specific property's flood zone designation before closing.
💨 Air varies by location
The worst air is along the Ship Channel and I-10 East corridor. Northwest neighborhoods — Katy (77494), Cypress (77429), Spring (77388) — score 15–20 points higher on air quality than eastern zip codes. Where you buy within Harris County matters enormously for air quality exposure.
💧 Water is safe but evolving
Most Harris County utilities pass current EPA standards. PFAS monitoring under UCMR 5 (2023–2025) is not yet fully published. The Gulf Coast Aquifer is under increasing subsidence stress from decades of groundwater withdrawal — some areas have subsided 10+ feet.
📈 Growth pressure is extreme
Adding 48,695 residents in one year is unprecedented. Impervious surface exceeds 40% in the urban core, intensifying flooding, urban heat, and green space loss. Harris County has no zoning — the fastest-growing county in America also has the least land-use regulation of any major US metro.
Zip code comparison
Selected neighborhoods| Zip / Area | Overall | Air | Water | Flood Risk | Urbanization | Verdict |
|---|---|---|---|---|---|---|
| 77494 — Katy (NW) | B+ / 77 | 67 | 74 | Low | Moderate | Best overall |
| 77429 — Cypress (NW) | B / 72 | 63 | 71 | Moderate | Moderate | Strong suburb |
| 77388 — Spring (N) | B- / 68 | 58 | 70 | Moderate | Moderate | Good value |
| 77584 — Pearland (S) | B- / 66 | 57 | 68 | Moderate | Moderate | Growing suburb |
| 77082 — Westchase (W) | C+ / 58 | 52 | 65 | Moderate | High | Flood watch |
| 77002 — Downtown Houston | C+ / 55 | 48 | 61 | High | Very high | Urban tradeoffs |
| 77015 — East Houston | D+ / 38 | 24 | 55 | High | High | Near Ship Channel |
Water filter guidance
What actually works💧 A Brita pitcher won't protect you from Harris County's water concerns
⚠ Important: Basic pitcher filters and carbon filters do NOT remove PFAS, arsenic, or nitrates — the three primary water concerns in Harris County. Only NSF/ANSI 58 certified reverse osmosis (RO) systems provide near-complete removal of these contaminants.
| Filter Type | PFAS | Arsenic | Nitrates | Lead | DBPs | Bacteria | Cost |
|---|---|---|---|---|---|---|---|
| Brita / Basic Pitcher | ✗ | ✗ | ✗ | ~ | ~ | ✗ | $30–50 |
| Certified Pitcher (NSF 53/473) | ~ | ✗ | ✗ | ✓ | ✓ | ✗ | $80–120 |
| Whole-House Carbon | ~ | ✗ | ✗ | ~ | ✓ | ✗ | $600–900 |
| Reverse Osmosis (NSF 58) ← Recommended | ✓ 99%+ | ✓ 95%+ | ✓ 95%+ | ✓ 99% | ✓ 99% | ~ | $300–500 |
Myth Buster:
"I just got a Brita — I'm protected." Reality: Duke University research (NC State / Nicholas School of the Environment) found that basic activated carbon filters — including many pitcher, countertop, and fridge filters — showed inconsistent and unpredictable PFAS removal. Some whole-house carbon systems actually increased PFAS levels in the water. For Harris County's industrial corridor contamination, a pitcher filter provides a false sense of security. Only NSF/ANSI 58 certified RO systems achieved near-complete PFAS removal in controlled testing.
Recommended for Harris County
Given PFAS monitoring from the Ship Channel corridor, naturally occurring arsenic in the Gulf Coast Aquifer, nitrates in outer Harris County MUDs, and Harvey-level flood contamination risk — a reverse osmosis system is the appropriate choice. Under-sink or countertop RO units cost $300–500 and filter water at pennies per gallon. Look for NSF/ANSI 58 certification and PFOA/PFOS specific certification.
AquaTru Countertop RO (~$350) →
Waterdrop G3 Under-Sink RO (~$350) →
Affiliate links — EarthScore360 earns a small commission at no cost to you. We only recommend NSF-certified systems verified to remove the contaminants present in Harris County's water supply.
FEMA Flood Zone Lookup
Free address-level check🌊 Is your specific address in a Harris County flood zone?
Harris County's overall flood score reflects county-wide risk — but your specific property may be in a dramatically higher or lower risk zone. 1 in 4 Harris County properties is in a FEMA flood zone. Enter your address to query the FEMA National Flood Hazard Layer in real time.
Data from FEMA National Flood Hazard Layer (NFHL) · Harris County MAAPnext maps updating in 2026 — some Zone X properties may be reclassified · For official flood determination use FEMA Map Service Center at msc.fema.gov
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All 7 risk domains
Zip-code breakdown
5-year trend charts
Printable PDF report
Live AQI data
Cited data sources
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Data from EPA, FEMA, FBI, ATSDR
Data from EPA, FEMA, FBI, ATSDR
DATA SOURCED FROM US FEDERAL AGENCIES · NOT REAL ESTATE ADVICE
Other Texas counties
Compare nearbyData sources
EPA AirNow & AQS 2024 · TCEQ Nonattainment Designations 2024 · Air Alliance Houston Report 2026 · EPA SDWIS · UCMR 5 PFAS Program · Harris County MUD CCR 2024 · USGS NLCD 2021 · FEMA MAAPnext 2026 · FEMA National Risk Index 2025 · ATSDR EJI 2024 · US Census Vintage 2025 · American Forests Tree Equity Score · FBI Crime Data Explorer 2024
EarthScore360 data is for informational purposes only. Scores are derived from publicly available federal and state government databases. This report does not constitute legal, environmental, real estate, or financial advice. Not a substitute for professional home inspection or environmental assessment. Data may not reflect most recent conditions. See full disclaimer at earthscore360.net. Governing law: State of Texas, Brazos County.