Facility Overview
Granite Rock Company Redwood City is operating under a active permit of type: Industrial. Primary industry: Ready. Secondary industry: Asphalt Paving Mixtures and Blocks. Tertiary industry: Scrap and Waste Materials.
The site has self-reported imperviousness of 70%. In the context of the Industrial General Permit for stormwater runoff, imperviousness refers to the percentage of the facility's surface area that doesn't allow water to penetrate, such as concrete, asphalt, or rooftops. The higher the imperviousness percentage, the more potential impact on local water quality as there is a greater surface area to accumulate pollutants.
In terms of water impact, the facility directly affects the Steinberger Creek and the downstream waters. This information is crucial for understanding the facility's potential environmental influence on local water resources.
Additional Details
The information displayed on the map and this report is derived from publicly available data, including reports submitted through the California State Water Resources Control Board's SMARTS database, and is provided for informational purposes only. Blanks or missing data reflects a lack of data provided by the facility or improperly uploaded data. Facilities identified on this map as having exceedances, missing reports, or other potential issues are flagged as suspected of non-compliance only. A flag on this map does not mean a facility has been found, or is, in violation of the IGP or any other law.
Historical Exceedances
This facility has historically exceeded limits for the following parameters:
pH
pH levels outside the normal range can harm aquatic life and affect water chemistry. Acidic water can leach toxic metals from sediments, while alkaline water can increase ammonia toxicity.
Iron, Total
Excessive iron can harm aquatic ecosystems by forming precipitates that smother habitats. It can also affect fish gills and reduce visibility in water.
Oil and Grease
Oil and grease can form films on water surfaces, reducing oxygen levels and harming aquatic life. They can also contaminate sediments and be toxic to organisms.
Total Suspended Solids (TSS)
High levels of suspended solids can reduce water clarity, harm fish gills, smother aquatic habitat and eggs, and transport pollutants through water bodies.
These limits reflect Water Quality Standards promulgated to protect human health or the environment, or standards that the State or EPA developed to indicate the Facility may be failing to implement best practices to protect storm water.
Most IGP facilities are required to collect storm water samples four times per year during qualifying storm events. Where fewer than four samples are shown below, the facility may not be meeting this requirement. When a facility fails to sample at the required frequency, or samples outside of qualifying events, the resulting data may not accurately reflect its actual discharges to receiving waters. As a result, missing or incomplete sampling data can make a facility's reports appear to show less environmental impact than is actually occurring.
Discharge Reports Summary
| Year | Sample Reports | Exceedances | Status |
|---|---|---|---|
| 2024 | 6 | 8 | Exceedances Detected |
| 2023 | 5 | 6 | Exceedances Detected |
| 2022 | 5 | 2 | Exceedances Detected |
| 2021 | 6 | 5 | Exceedances Detected |
| 2020 | 6 | 3 | Exceedances Detected |
| 2019 | 5 | 6 | Exceedances Detected |
| 2018 | 14 | 22 | Exceedances Detected |
| 2017 | 8 | 11 | Exceedances Detected |
| 2016 | 6 | 10 | Exceedances Detected |