Home > Analysis: 7147 Hemlock St, Houston, TX 77087 10/22/2025

📊 Environmental Assessment Report

This comprehensive report analyzes both flood risk and industrial pollution exposure for this property. The assessment combines multiple data sources including USGS elevation, FEMA flood zones, historical storm modeling, and EPA Toxic Release Inventory records.

🌊 Part 1: Flood Risk Analysis

Property Overview

This section shows the fundamental characteristics of the property, including its elevation above sea level, FEMA flood zone designation, and our calculated overall flood risk rating based on historical data and topographic analysis.

Address

7147 HEMLOCK ST HOUSTON 77087

Building Size

1,312 sqft

Total structure area from HCAD building records.

Elevation

32.5 ft

Height above sea level from USGS data.

FEMA Flood Zone

Moderate to Low Risk - Outside 500-year floodplain

Overall Risk

Very Low

Risk based on FEMA zone and simulation.

Risk Assessment Outputs

These detailed metrics show the technical outputs from our flood risk model. They include predicted water depths at the property during a 5000-year flood event and estimated flood damage based on USACE methodology.

Risk Rating

Very Low

Flood Depth

0 ft ±0.5 ft

No flooding at current water level.

Water Surface Elevation (WSE)

N/A

Water surface elevation data not available.

Area Inundated

N/A

Data not available

Nearest Bayou Stage

N/A

No nearby bayou within monitoring range

Depth-Damage Estimate (HCAD Valuation)

Property not flooded at current water level. No damage to calculate.

Depth-Damage Estimate (Neighborhood Comparison)

Property not flooded at current water level. No damage to calculate.

Analysis Method

COG Bathtub Model

Raster-based flood inundation query

Flood Simulation

This simulation shows whether the property would flood based on a 5000-year flood event with 3m (9.84ft) water level. Use the interactive tool to explore different scenarios.

✅ Property Would Be Safe

Safety Margin: 22.5 feet
Severity: Safe

Adjust Flood Simulation

The analysis above uses default settings (5000-year flood, 3m/9.84ft water level). To explore different flood scenarios with interactive maps, return to the main tool:

Open Interactive Analysis Tool

Flood Risk Recommendations

Based on the property's flood risk profile, here are specific action items to consider.

FEMA Zone X (minimal hazard) - flood insurance available at preferred rates.
Review the interactive flood simulator to understand how different rainfall events could affect this property.
Contact Harris County Flood Control District (HCFCD) for drainage projects and flood information.

🏭 Part 2: Industrial Pollution Exposure

Property Pollution Ranking

High

Higher pollution than 83% of Houston homes

This ranking compares pollution levels within 2 miles of this property against 10,000 randomly sampled Houston metro properties. Lower percentiles indicate higher pollution exposure.

Industrial Pollution Nearby (Last 10 Years)

1.49 million lbs

Extremely High

228.6x more than typical Houston property
≈ 75 dump trucks of chemicals within 2 miles

Total chemical releases from all industrial facilities within a 2-mile radius over the past decade (2014–2024). Data from EPA's Toxic Release Inventory tracking air, water, and land discharges.

💨 Air Pollution (Last 10 Years)

1.45 million lbs

Extremely High

300.2x more than typical Houston property

Chemicals released into the air from nearby facilities over 10 years. Includes both fugitive emissions (leaks, evaporation) and stack emissions (smokestacks, vents). May affect local air quality.

💧 Water Pollution (Last 10 Years)

44 thousand lbs

Extremely High

Chemical discharges to surface water (bayous, streams, drainage) from industrial facilities within 2 miles over the past decade. May impact local waterways and drainage systems.

❤️ Why It Matters

High chemical activity nearby can indicate industrial zones, truck traffic, or potential odor and noise issues. These factors may affect air quality, long-term property desirability, and neighborhood character. This data helps you understand the industrial footprint around your property.

🏙️ Houston Metro Benchmarks

Comparison with typical Houston properties (based on 10,000 randomly sampled homes). All measurements are for chemicals released within a 2-mile radius.

Period	Total	Air	Water
Typical Houston Property (2014-2024)	6,524 lbs	4,822 lbs	0 lbs
This Property (2014-2024)	1,491,393 lbs	1,447,708 lbs	43,686 lbs
Typical Houston Property (2024 Only)	2 lbs	1 lbs	0 lbs
This Property (2024 Only)	737,072 lbs	115,762 lbs	14,568 lbs

📊 How This Property Compares to Houston Metro

Based on a random sample of 10,000 Houston properties, this chart shows the distribution of pollution levels across the metro area. The highlighted bar indicates where this property falls compared to other homes. Lower percentiles mean higher pollution exposure.

0-9thMost Polluted

9.9%

10-19th

10.1%

20-29th

9.9%

30-39th

10.1%

40-49th

9.7%

50-59th

10.2%

60-69th

70-79th

5.8%

80-89th

4.3%

90-100thLowest Pollution

34.2%

Higher pollution than 83% of Houston homes

Each bar's width represents the percentage of Houston homes in that pollution range. This property ranks in the 10-19th percentile (top 15% most polluted).

Top chemicals released near this property (past 10 years):

Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size), Ammonia, Methyl tert-butyl ether, 1,3-Butadiene, Methanol

View the full list of 40 chemicals below.

Chemicals Released (2014-2024, 10-Year Total) (40 chemicals)

#	Chemical	CAS#	Air (lbs, 10yr)	Water (lbs, 10yr)	Total (lbs, 10yr)
1	Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)	7664-93-9	376,938	0	376,938
2	Ammonia	7664-41-7	331,114	3,674	334,788
3	Methyl tert-butyl ether	1634-04-4	267,534	0	267,534
4	1,3-Butadiene	106-99-0	255,579	0	255,579
5	Methanol	67-56-1	56,340	39,325	95,666
6	Xylene (mixed isomers)	1330-20-7	65,543	0	65,543
7	N,N-Dimethylformamide	68-12-2	22,161	88	22,249
8	tert-Butyl alcohol	75-65-0	15,278	0	15,278
9	Ethylene glycol	107-21-1	14,690	0	14,690
10	Propylene	115-07-1	14,432	0	14,432
11	1,4-Dioxane	123-91-1	10,779	0	10,779
12	Hydrogen sulfide	7783-06-4	6,306	0	6,306
13	Ethylene	74-85-1	2,621	0	2,621
14	Phthalic anhydride	85-44-9	2,000	0	2,000
15	Vinyl acetate	108-05-4	1,608	0	1,608
16	Manganese	7439-96-5	1,000	331	1,331
17	Acetaldehyde	75-07-0	1,011	0	1,011
18	Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)	7647-01-0	999	0	999
19	Lead	7439-92-1	622	256	878
20	1,1,1,2-Tetrachloroethane	630-20-6	434	0	434
21	Carbon disulfide	75-15-0	351	0	351
22	Dimethylamine	124-40-3	90	0	90
23	Lead And Lead Compounds	N420	63	10	73
24	Vanadium compounds	N770	65	0	65
25	Boron trifluoride	7637-07-2	36	0	36
26	Allyl alcohol	107-18-6	34	0	34
27	Methoxone sodium salt	3653-48-3	20	0	20
28	Triethylamine	121-44-8	17	0	17
29	Acrolein	107-02-8	13	0	13
30	Hydroquinone	123-31-9	9	0	9
31	Diaminotoluene (mixed isomers)	25376-45-8	4	0	4
32	Mercury compounds	N458	3	1	4
33	Pyridine	110-86-1	3	0	3
34	Benzene	71-43-2	3	0	3
35	Chloroethane	75-00-3	2	0	2
36	p-Cresol	106-44-5	2	0	2
37	2,4-Diaminotoluene	95-80-7	1	0	1
38	Trichloroethylene	79-01-6	1	0	1
39	Ethylbenzene	100-41-4	1	0	1
40	Cyclohexane	110-82-7	1	0	1

Top chemicals released near this property (2024 only):

1,4-Dioxane, Ethylene glycol, Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size), Methanol, Methyl tert-butyl ether

View the full list of 22 chemicals reported within 2 miles for 2024.

Chemicals Released (2024 Only) (22 chemicals)

#	Chemical	CAS#	Air (lbs/yr)	Water (lbs/yr)	Total (lbs/yr)
1	1,4-Dioxane	123-91-1	328	0	396,851
2	Ethylene glycol	107-21-1	5,094	0	177,549
3	Sulfuric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)	7664-93-9	50,698	0	50,698
4	Methanol	67-56-1	7,001	14,541	45,817
5	Methyl tert-butyl ether	1634-04-4	18,336	0	31,624
6	1,3-Butadiene	106-99-0	18,236	0	18,236
7	Xylene (mixed isomers)	1330-20-7	10,496	0	10,496
8	N,N-Dimethylformamide	68-12-2	1,641	0	1,842
9	Propylene	115-07-1	1,091	0	1,091
10	tert-Butyl alcohol	75-65-0	1,021	0	1,021
11	Hydrogen sulfide	7783-06-4	592	0	592
12	Ethylene	74-85-1	364	0	364
13	Carbon disulfide	75-15-0	241	0	241
14	Hydrochloric acid (acid aerosols including mists, vapors, gas, fog, and other airborne forms of any particle size)	7647-01-0	221	0	221
15	1,1,1,2-Tetrachloroethane	630-20-6	212	0	212
16	Ammonia	7664-41-7	107	0	107
17	Lead	7439-92-1	20	22	42
18	Lead And Lead Compounds	N420	31	5	36
19	Dimethylamine	124-40-3	23	0	23
20	Vinyl acetate	108-05-4	5	0	5
21	Boron trifluoride	7637-07-2	1	0	1
22	Acetaldehyde	75-07-0	1	0	1