Enter the average annual rainfall for the landfill location.
The total surface area of the active or closed cell.
Open active cell (High infiltration – 50%)
Intermediate cover (Moderate infiltration – 25%)
Clay cap (Low infiltration – 10%)
Geomembrane cap (Very low infiltration – 2%)
Custom Percentage
Annual Leachate Volume:– m³/year
Daily Average Volume:– m³/day
Daily Volume (Liters):– L/day
About Leachate Generation Rate
Calculating the leachate generation rate is a critical component of landfill management and design. Leachate is the liquid that drains or "leaches" from a landfill. It varies widely in composition depending on the age of the landfill and the type of waste that it contains. It usually consists of both dissolved and suspended materials.
The Calculation Formula
This calculator utilizes the Rational Method (often adapted as the Swiss Method in waste management contexts) to estimate the potential volume of leachate generated based on precipitation and surface characteristics. The simplified formula used is:
V = P × A × K
V: Total volume of leachate generated (m³).
P: Precipitation (rainfall) in meters.
A: Surface area of the landfill cell in square meters (m²).
K: Infiltration coefficient (a percentage representing how much rain enters the waste mass versus running off or evaporating).
Understanding the Inputs
Annual Precipitation: This is the primary driver of leachate generation. Areas with high rainfall will naturally generate more leachate requiring treatment.
Surface Area: The "footprint" of the landfill cell exposed to the elements.
Surface Condition (Coefficient):
Open active cell: Without cover, waste is porous, leading to high infiltration rates (often 40-60%).
Final cap: Engineered caps with clay or geomembranes significantly minimize leachate generation (often <10%).
Why is this calculation important?
Accurate estimation of leachate generation rates is essential for sizing leachate collection systems (pipes and sumps), designing storage lagoons, and determining the capacity requirements for on-site or off-site wastewater treatment plants. Underestimating these rates can lead to environmental contamination and regulatory fines, while overestimating can result in unnecessary infrastructure costs.
function toggleCustomCoeff() {
var select = document.getElementById("coeffSelect");
var customGroup = document.getElementById("customCoeffGroup");
if (select.value === "custom") {
customGroup.style.display = "block";
} else {
customGroup.style.display = "none";
}
}
function calculateLeachate() {
// 1. Get Input Values
var precipMm = parseFloat(document.getElementById("precipInput").value);
var areaM2 = parseFloat(document.getElementById("areaInput").value);
var selectVal = document.getElementById("coeffSelect").value;
var coeffPercent = 0;
// 2. Validate Numbers
if (isNaN(precipMm) || precipMm < 0) {
alert("Please enter a valid positive number for Precipitation.");
return;
}
if (isNaN(areaM2) || areaM2 < 0) {
alert("Please enter a valid positive number for Area.");
return;
}
// 3. Determine Coefficient
if (selectVal === "custom") {
coeffPercent = parseFloat(document.getElementById("customCoeffInput").value);
if (isNaN(coeffPercent) || coeffPercent 100) {
alert("Please enter a valid percentage (0-100) for the Custom Infiltration Rate.");
return;
}
} else {
coeffPercent = parseFloat(selectVal) * 100;
}
// 4. Perform Calculation
// Formula: Volume (m3) = (Precip (mm) / 1000) * Area (m2) * (Percent / 100)
var precipMeters = precipMm / 1000;
var efficiencyFactor = coeffPercent / 100;
var annualVolumeM3 = precipMeters * areaM2 * efficiencyFactor;
var dailyVolumeM3 = annualVolumeM3 / 365;
var dailyVolumeLiters = dailyVolumeM3 * 1000;
// 5. Update UI
document.getElementById("volYearResult").innerHTML = annualVolumeM3.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}) + " m³/year";
document.getElementById("volDayM3Result").innerHTML = dailyVolumeM3.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2}) + " m³/day";
document.getElementById("volDayLitersResult").innerHTML = dailyVolumeLiters.toLocaleString(undefined, {minimumFractionDigits: 0, maximumFractionDigits: 0}) + " L/day";
document.getElementById("resultsDisplay").style.display = "block";
}