Soil and Water Quality

IRIS Mitigation and Design, Inc. (IRIS) conducts soil sampling and soil quality analysis early on in project design to assist in appropriate plant selection and soil amendment planning. IRIS collects soil samples from topsoil, subsoil, and stockpiled topsoil areas separately as necessary. IRIS also recommends sampling imported topsoil before it is brought on-site to determine soil quality and whether further soil amendments will be necessary. IRIS delivers soil samples to a soil testing laboratory and provides soil amendment recommendations tailored to what will be seeded and planted on the site.

 

IRIS tests for a minimum of the following soil condition parameters:

 

  • Soil Texture - characterizes soil into a percentage of sand, clay, and/or silt based on particle size to assist with appropriate plant species selection.
  • pH – measures the hydrogen ion activity in solution. A pH of less than 6 indicates acidic soil conditions while a pH greater than 8.0 indicates alkaline soil conditions. A soil pH of 6.5 is best for plant nutrient availability.
  • Electrical Conductivity (EC) - measures the amount of free salt in soil. Soils with greater than 4 mmhos/cm may have elevated saline conditions.
  • Free Lime– determines the amount of calcium carbonate and magnesium in the soil. Too much or too little lime in the soil poses differing issues for vegetation establishment.
  • Nitrogen (N) – Phosphorus(P) – Potassium(K) are standard soil nutrient indicators for plant vigor and health depending on concentrations in the soil.
  • Saturation Percentage – is the amount of water needed to saturate soil (percentage by weight). Results of greater than 80 may indicate high clay content and/or high sodium quantities. Results of less than 25 may indicate more sandy soil content with low water-holding capacity.
  • Organic Matter Content – Good topsoil should contain at least 2% organic matter.
  • Exchangeable Cations – Calcium (Ca), Magnesium (Mg), Sodium (Na), and Potassium (K) are standard indicators for plant growth, vigor and health depending on concentrations in the soil.
  • Sodium and Sodium Absorption Ratio (SAR) – SAR is an indirect measure of the percentage of exchangeable sodium on the soil particle. Values of less than 6 are desirable for topsoil. Soils with higher sodium conditions will require salt tolerant plant species selection.

Once the soil has been tested and the results analyzed, soil amendments may be needed to improve soil condition prior to seeding and planting the site. IRIS will assist in explaining the soil test results and what additional soil amendments may be needed. If amendments are needed based on the soil test, amendments may include but are not limited to: slow release organic fertilizers, chemical fertilizers, compost, peat, humates, sulfur, gypsum, lime, wood chips and soil micro-organisms.

Many sites with low organic matter (including overworked agricultural soils, steep slopes, and sub-soils) will benefit from the addition of a slow release organic fertilizer. Chemical fertilizers are avoided as they generally have higher phosphorus and nitrogen levels, which encourage weedy growth that competes with the desirable planted and seeded species. IRIS will assist in soil amendment selection, application and integration prior to seeding and planting the site.

 

Water Quality Sampling and Analysis
Understanding and managing water quality is essential for overall aquatic resource management. The most common pond and lake problems such as excess weeds, poor water color, offensive odors, rapid sludge accumulation, and fish kills are a result of compromised water quality. High nutrient content can result in excess weed and algae growth, which in turn can lead to other problems. Because of the important effect of water quality on pond and lake management, understanding and improving water quality is a crucial part of aquatic resource management.

IRIS Mitigation and Design, Inc. assists with water quality issues by completing overall lake and pond area assessments and by collecting water and aquatic vegetation samples for analysis. The following water quality parameters are tested for and analyzed for overall water quality pond conditions:
Depending on existing pond conditions and following water quality sampling analysis IRIS will recommend a combination of the following lake and pond treatments:

 

  • Alkalinity (as CaCO3)
  • Ammonia – Total
  • Conductivity
  • Dissolved solids – Total
  • Hardness (as CaCO3)
  • Iron
  • Magnesium
  • Manganese
  • Nitrate as Nitrogen
  • pH
  • Phosphorous
  • Potassium
  • Sodium
  • Sulfate
  • Turbidity
  • Zinc
 
  • Aeration systems are beneficial for more shallow ponds and lakes by adding oxygen, increasing water circulation, and through promoting anaerobic decay of organic materials, ideally reducing phosphorus concentrations and increasing the carrying capacity of the pond.
  • Beneficial bacterial treatments (often coupled with aeration) will continue to improve water clarity, reduce nutrient content, lessen odors, and decrease sludge accumulation. Bacterial treatments will also help control aquatic vegetation without the use of chemicals.
  • Fish introduction (such as grass carp) assist in naturally controlling aquatic vegetation without the use of chemicals.
  • The use of low phosphorous fertilizer and low/slow release nitrogen in chemical fertilizers used on lawns and common landscaped areas is desirable near aquatic sites to reduce unnatural aquatic plant and algae growth in the water bodies due to high nutrients in storm water runoff.
  • Chemical herbicide and algaecide applications assist in controlling aquatic plant and algae.
  • Wetland and riparian plant establishment of a variety of native species will assist in nutrient capture and removal from the aquatic system and will establish desirable native vegetation for both wildlife habitat and aesthetic purposes.
  • Annual water quality testing and analysis allows for tracking of how pond and lake treatments are improving the aquatic resource conditions over time. Annual test results assist with further management planning to maintain and maximize improvements into the future.